Whitelisted IP in Cloudflare yet MainWP child plugin will not activate in WP. Strange as all other sites are activating and installing.
Welcome to the MainWP community.
If you cannot activate the MainWP Child plugin in the WP Admin of your child site, then the issue is likely not caused by Cloudflare, and it’s very likely not a MainWP specific issue.
What error do you get when you try to activate the MainWP Child plugin?
Can you activate other plugins on that site?