At least on itwiki, since a few days we noticed that all edits are tagged as advanced mobile edits. See for instance the last 500 RC entries: ctrl+f says there are 473 "advanced mobile edit" matches.
Needless to say, this is super-confusing for people, especially if they see their contributions tagged as mobile while they contribute from desktop.
I looked at the code, and while grepping doesn't help much, I see that the tag is applied where one would expect it, i.e. in the RecentChange_save hook handler, here. Looking at the method which decides whether the edit should be tagged, the docs suggest that it only checks whether AMC is enabled for the current user, and not whether the current edit is also an AMC edit (and the same goes for UserMode::isEnabled).