Sep 21 2019
On en.m.wikipedia.org, go to Special:MobileOptions and turn on the one that says “Advanced mode”. I’m using Safari and it started on Friday, but seems to work now.
Sep 14 2019
There wasn't a specific filter, but when I attempted to undo an edit such as https://ru.wikipedia.org/w/index.php?title=Обсуждение_участника:OneLittleMouse&diff=102153289&oldid=102153267&diffmode=source this, I tripped the edit filter.