I see the problem (but not a fix yet). As everyone now accesses the forum through Cloudflare the forum sees you all coming from one of a limited number of Cloudflare ‘egress’ IP addresses. Now that’s not a problem, many ISPs have proxies that combine all their users into a limited number of IP addresses so the forum can live with that.
The problem is that ‘dodgy’ users trying to hack/attack/spam domains access those domains through Cloudflare because the domain owners, like me, want the extra protection Cloudflare provide. That means the Cloudflare egress IPs get associated with the dodgy things that hackers/spammers do and therefore firewalls that act on those IPs associated with dodgy users ‘block’ legitimate users who are seen on those same IP addresses. I hope that makes sense.
My thoughts at the moment are…I can disable the dodgy user checks but I’m not sure if that will lead to more dodgy users in the forum or I can look for a way for the forum firewall mod to ignore the Cloudflare IPs. I’ll have to see what’s possible and what the impact of any solution is likely to be. Please bear with me whilst I investigate and consider the options.