Bende de aynı sorun oluştu, cyberpanel kullanıyorum uyarıda php tarafında fsockopen ve gethostbynamel fonksiyonlarının açık olması gerektiğini yazmışlar kontrol ettim sorun yok.
Ek olarakTcp bağlantısı yapması gerekiyormuş. Güvenlik duvarı kurallarına baktım ama çözemedim. Eklenti veya sunucu kaynaklı gibi, güncelleme yaptıktan sonra bu uyarı çıkmaya başladı çünkü.

# iptables -L
Chain INPUT (policy DROP)
target     prot opt source               destination        
LOCALINPUT  all  --  anywhere             anywhere            
ACCEPT     all  --  anywhere             anywhere            
INVALID    tcp  --  anywhere             anywhere            
ACCEPT     icmp --  anywhere             anywhere             icmp echo-request limit: avg 1/sec burst 5
LOGDROPIN  icmp --  anywhere             anywhere             icmp echo-request
ACCEPT     icmp --  anywhere             anywhere            
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:ftp-data
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:ftp
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:ssh
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:smtp
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:domain
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:http
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:pop3
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:imap
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:https
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:urd
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:submission
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:imaps
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:pop3s
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:blackjack
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:8090
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpts:40110:40210
ACCEPT     udp  --  anywhere             anywhere             ctstate NEW udp dpt:ftp-data
ACCEPT     udp  --  anywhere             anywhere             ctstate NEW udp dpt:ftp
ACCEPT     udp  --  anywhere             anywhere             ctstate NEW udp dpt:domain
LOGDROPIN  all  --  anywhere             anywhere            

Chain FORWARD (policy DROP)
target     prot opt source               destination        

Chain OUTPUT (policy DROP)
target     prot opt source               destination        
LOCALOUTPUT  all  --  anywhere             anywhere            
ACCEPT     tcp  --  anywhere             anywhere             tcp dpt:domain
ACCEPT     udp  --  anywhere             anywhere             udp dpt:domain
ACCEPT     tcp  --  anywhere             anywhere             tcp spt:domain
ACCEPT     udp  --  anywhere             anywhere             udp spt:domain
ACCEPT     all  --  anywhere             anywhere            
INVALID    tcp  --  anywhere             anywhere            
ACCEPT     icmp --  anywhere             anywhere            
ACCEPT     all  --  anywhere             anywhere             ctstate RELATED,ESTABLISHED
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:ftp-data
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:ftp
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:ssh
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:smtp
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:nicname
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:domain
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:http
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:pop3
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:auth
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:https
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:urd
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:submission
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:imaps
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:pop3s
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpt:8090
ACCEPT     tcp  --  anywhere             anywhere             ctstate NEW tcp dpts:40110:40210
ACCEPT     udp  --  anywhere             anywhere             ctstate NEW udp dpt:ftp-data
ACCEPT     udp  --  anywhere             anywhere             ctstate NEW udp dpt:ftp
ACCEPT     udp  --  anywhere             anywhere             ctstate NEW udp dpt:domain
ACCEPT     udp  --  anywhere             anywhere             ctstate NEW udp dpt:auth
ACCEPT     udp  --  anywhere             anywhere             ctstate NEW udp dpt:ntp
LOGDROPOUT  all  --  anywhere             anywhere            

Chain ALLOWIN (1 references)
target     prot opt source               destination        

Chain ALLOWOUT (1 references)
target     prot opt source               destination        

Chain DENYIN (1 references)
target     prot opt source               destination        

Chain DENYOUT (1 references)
target     prot opt source               destination        

Chain INVALID (2 references)
target     prot opt source               destination        
INVDROP    all  --  anywhere             anywhere             ctstate INVALID
INVDROP    tcp  --  anywhere             anywhere             tcp flags:FIN,SYN,RST,PSH,ACK,URG/NONE
INVDROP    tcp  --  anywhere             anywhere             tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,SYN,RST,PSH,ACK,URG
INVDROP    tcp  --  anywhere             anywhere             tcp flags:FIN,SYN/FIN,SYN
INVDROP    tcp  --  anywhere             anywhere             tcp flags:SYN,RST/SYN,RST
INVDROP    tcp  --  anywhere             anywhere             tcp flags:FIN,RST/FIN,RST
INVDROP    tcp  --  anywhere             anywhere             tcp flags:FIN,ACK/FIN
INVDROP    tcp  --  anywhere             anywhere             tcp flags:PSH,ACK/PSH
INVDROP    tcp  --  anywhere             anywhere             tcp flags:ACK,URG/URG
INVDROP    tcp  --  anywhere             anywhere             tcp flags:!FIN,SYN,RST,ACK/SYN ctstate NEW

Chain INVDROP (10 references)
target     prot opt source               destination        
DROP       all  --  anywhere             anywhere            

Chain LOCALINPUT (1 references)
target     prot opt source               destination        
ALLOWIN    all  --  anywhere             anywhere            
DENYIN     all  --  anywhere             anywhere            

Chain LOCALOUTPUT (1 references)
target     prot opt source               destination        
ALLOWOUT   all  --  anywhere             anywhere            
DENYOUT    all  --  anywhere             anywhere            

Chain LOGDROPIN (2 references)
target     prot opt source               destination        
DROP       tcp  --  anywhere             anywhere             tcp dpt:telnet
DROP       udp  --  anywhere             anywhere             udp dpt:telnet
DROP       tcp  --  anywhere             anywhere             tcp dpt:bootps
DROP       udp  --  anywhere             anywhere             udp dpt:bootps
DROP       tcp  --  anywhere             anywhere             tcp dpt:bootpc
DROP       udp  --  anywhere             anywhere             udp dpt:bootpc
DROP       tcp  --  anywhere             anywhere             tcp dpt:sunrpc
DROP       udp  --  anywhere             anywhere             udp dpt:sunrpc
DROP       tcp  --  anywhere             anywhere             tcp dpt:auth
DROP       udp  --  anywhere             anywhere             udp dpt:auth
DROP       tcp  --  anywhere             anywhere             tcp dpts:epmap:netbios-ssn
DROP       udp  --  anywhere             anywhere             udp dpts:epmap:netbios-ssn
DROP       tcp  --  anywhere             anywhere             tcp dpt:microsoft-ds
DROP       udp  --  anywhere             anywhere             udp dpt:microsoft-ds
DROP       tcp  --  anywhere             anywhere             tcp dpt:isakmp
DROP       udp  --  anywhere             anywhere             udp dpt:isakmp
DROP       tcp  --  anywhere             anywhere             tcp dpt:login
DROP       udp  --  anywhere             anywhere             udp dpt:who
DROP       tcp  --  anywhere             anywhere             tcp dpt:efs
DROP       udp  --  anywhere             anywhere             udp dpt:router
LOG        tcp  --  anywhere             anywhere             limit: avg 30/min burst 5 LOG level warning prefix "Firewall: *TCP_IN Blocked* "
LOG        udp  --  anywhere             anywhere             limit: avg 30/min burst 5 LOG level warning prefix "Firewall: *UDP_IN Blocked* "
LOG        icmp --  anywhere             anywhere             limit: avg 30/min burst 5 LOG level warning prefix "Firewall: *ICMP_IN Blocked* "
DROP       all  --  anywhere             anywhere            

Chain LOGDROPOUT (1 references)
target     prot opt source               destination        
LOG        tcp  --  anywhere             anywhere             tcp flags:FIN,SYN,RST,ACK/SYN limit: avg 30/min burst 5 LOG level warning uid prefix "Firewall: *TCP_OUT Blocked* "
LOG        udp  --  anywhere             anywhere             limit: avg 30/min burst 5 LOG level warning uid prefix "Firewall: *UDP_OUT Blocked* "
LOG        icmp --  anywhere             anywhere             limit: avg 30/min burst 5 LOG level warning uid prefix "Firewall: *ICMP_OUT Blocked* "
REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable