BUG Hierarchie / Baum verändern kaputt

[timbuktutimbuktu]

BUG
ich kann die Hierarchie von Tasks nicht mehr verändern.
Selbst wenn ich als admin angemeldet bin, führt ein verschieben per drag&drop nur zu einem freundlich gelben blinken.
Es wird erst "as sibling" "as child" und die violette graphische Vorhersage angezeigt, aber wenn ich den mouse button loslasse, ist die task nicht verschoben, sondern blinkt gelb.
Help! 🚁

[kleins05]

Cannot be reproduced on local installation. Cannot test online because I do not have a user and don't know how to get one (I missed out on some information here, I think)

[fblampe]

I could reproduce it on the production and testing instances.

As @cafischer suggested, this might be related to errors logged in the browser console regarding our content security policy. I'm not so sure about that though because those errors also occur when just loading any admin page through a GET request.
There are no errors in the app log and the nginx logs only show the same 403 Forbidden status (which does look like a CSP issue..) as the browser debug tools network tab:

"POST /admin/cpmonitor/task/?city__id__exact=11 HTTP/1.1" 403

I'm not really sure what to make of this. Maybe the easiest way to find the commit that caused this is to use git bisect, provided the bug is reproducible in a local setup (probably running in Docker).