This is what my dual messenger looks like. They're not being applied so I don't think that is the issue but you can see how that grey square shows up everywhere.
Same as mine so that's not it , looks similar to assistant menu but it's not , but double check there in settings>accessibility>interactions and dexetry is it on assistant menu?
Boho, it maybe the Assistant Menu.
Check at Settings > Accessibility > Interaction and dexterity > Assistant menu. See if the toggle is on or off. If on, try turning it off.
Hope this helps...??