Pop-up menus etc. appear on wrong head or don't appear at all for windows on secondary head

Running mutter-3.35.92-2.fc32.x86_64 (Fedora 32) with two displays, things like right-click menus, tooltips, and menus spawned from buttons on the URL bar in Firefox behave wrongly for windows on the secondary display.

I have my displays side-by-side, the primary display is the left-hand one. Everything is fine for windows on that display. However, for windows on the secondary (right-hand) display that are maximized or pushed against the boundary between the heads (the left-hand side of the secondary display), such menus don't appear where they should, but on the right-hand side of the primary display (with the correct vertical position). For windows on the secondary display that are not maximized or pushed against the boundary between the heads, such menus are not visible at all.

This seems to affect native Wayland apps - at least Firefox (Wayland-native by default on Fedora), Evolution, gedit and virt-manager are affected. hexchat is not affected, and I believe that's an X app.

Attaching a screenshot showing the 'pop-up menu in wrong place' incarnation of the bug.