MainWP Child plugin not detected. First, install and activate the plugin and add your site to your MainWP Dashboard afterward. If you continue experiencing this issue, check the child site for known plugin conflicts, or check the MainWP Community for help.
I do cron every hour to check for updates, last sync varies from Sep 28 to Oct 2.
Just as sudden most sites are back in controlpanel, two are still disconnected
No CF and no security-plugins that could cause problems
The potential issues-page didn’t help much either. Of course it could be the server blocking calls to the site(s) specifically, but I doubt it. I guess most blocks are set server-wide.
I’ll try to migrate the MainWP Dashboard-site to a VPS and see if that helps
This is actually one of the most common reasons that I have seen. Please make sure that your Dashboard IP is whitelisted in child site server firewall.
Let us know how it goes after moving the dashboard.