Howdy.
I have just recently had to disable plugins on a site because of issues with Elementor, which I have now solved.
In the process, I deactivated MainwWP Child & Child Reports plugins - since reactivating them, I get the Warning message about connecting the Child site to the MainWp dashboard, however, I can no no longer access the MainWP Child plugin settings, via either the link on that warning or via the Settings menu.
Everything else on the site is functioning as normal, but when I try to access the settings it times out - here’s a screenshot of the timeout: