This is a strange one. I use Cerber on a number of sites, two of them are blocking MainWP with a 403 error. I have already whitelisted the IP and disabled bots. I don’t think the bots thing has anything to do with it though since other sites are working. These two sites use Cloudflare to improve uptime and throughput but it is not Cloudflare that is blocking the access. When I disable Cerber they connect just fine. I did that and connected the MainWP and turned Cerber back on and it all worked for about 12 hours and is now blocked again. I have no idea what settings to change in Cerber to make this work.
Do you know the IP address from which MainWP is connecting to your website?
Yes and it has been whitelisted as are the IP’s used by Cloudflare even though those shouldn’t matter.
Still looking for support on this. I have found no answers in the Cerber help articles or in this forum.