Hey @Martin A. - found a problem.
With this installed, I tried to create a new membergroup (unrelated task) and it threw an error and ultimately jacked up my ACP.
TypeError: Argument 1 passed to IPS\communitymap\Members\_Groups::getData() must be of the type integer, null given, called in /home/mysite/public_html/forums/applications/communitymap/extensions/core/GroupForm/communitymap.php on line 40 (0) #0 /home/mysite/public_html/forums/applications/communitymap/extensions/core/GroupForm/communitymap.php(40): IPS\communitymap\Members\_Groups::getData(NULL) #1 /home/mysite/public_html/forums/applications/core/modules/admin/members/groups.php(207): IPS\communitymap\extensions\core\GroupForm\_communitymap->process(Object(IPS\Helpers\Form), Object(IPS\Member\Group)) #2 /home/mysite/public_html/forums/system/Dispatcher/Controller.php(90): IPS\core\modules\admin\members\_groups->form() #3 /home/mysite/public_html/forums/applications/core/modules/admin/members/groups.php(39): IPS\Dispatcher\_Controller->execute() #4 /home/mysite/public_html/forums/system/Dispatcher/Dispatcher.php(152): IPS\core\modules\admin\members\_groups->execute() #5 /home/mysite/public_html/forums/admin/index.php(14): IPS\_Dispatcher->run() #6 {main}