Do Wandering Monsters “reset” the turn order?

[Parzival]

This is an issue that keeps happening with the HQ App.
When a player draws a Wandering Monster Treasure Card, the monster immediately appears and attacks (but does not move). So far, so good. By the rulebook, the target of the monster may then continue his or her turn, presumably to move away, as the Action part was drawing the blasted card. And then so-on to Zargon’s next turn.
But in the App, after attacking with the Monster, declares “Heroes’ Turn” and resets the heroes’ turn in full, technically allowing any heroes who had already moved and taken action to now move again and take other actions— including the targeted hero. In the meantime, any heroes who would have acted *after* the WM attack are essentially delayed in action. (They haven’t really lost a turn because they hadn’t acted anyway and got skipped, but it also hasn’t been Zargon’s turn, either, so there’s no net negative.)

I suspect this is an issue with the App (call it a bug if you favor Zargon, a “feature” if you favor the heroes). But is this the way others read the Wandering Monster sequence as working? I went through the rule book (2021 and First Light) very carefully, and I can’t find support for the App’s approach.