When I try to visit http://arcadesiteforum.arcadesite.me, it redirects me to suspended domains though I own the domain and retrobit.epizy.com is pointed to arcadesiteforum.arcadesite.me via CNAME
For me retrobit.epizy.com works perfectly.
As for the other domain, in your client Area should be a message about why it is suspended.
Send a support ticket and they will help you, otherwise wait for @Admin to answer.
The domain arcadesiteforum.arcadesite.me is not actually added to any hosting account, which is why it doesn’t show your website.
You need to actually add your domain to your hosting account to use it. Simply pointing it to our nameservers or the IP address of your hosting account will not show your website on it. After all, the servers don’t know which website to show on your domain if they don’t know the domain.
Please follow this instructions to add the domain to your account: How to add your own domain to your account - Docs - InfinityFree Forum