Service won't start if entering IP address

Just installed CSF on Centos 7.7 with Cpanel 84 and I already have a problem. If the CSF code has an IP entry in the deny file, the service won’t start at all. I get the following message in that case:
LOG icmpv6 opt in * out * ::/0 -> ::/0 limit: avg 30/min burst 5 LOG flags 8 level 4 prefix "Firewall: ICMP6OUT Blocked "
I am a new guy when it comes to CSF so advices and tips are more than welcome folks!