I always use before Debian 9, later 10. Very stabile. From Yesterday I choose new CentOS 8.0 core and randomly:
Unable to connect
Firefox can’t establish a connection to the server at xxx.xxx.xxx.xxx:8888.
The site could be temporarily unavailable or too busy. Try again in a few moments.
If you are unable to load any pages, check your computer’s network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the Web.
I think only the first time i make any bad thing, but today I must again reinstall the server(partitions and change SSD) and after 5. restart again not working the link. The sites running without problem the aaPanel no.