I use Thunderbird as my main Matrix client since it's already always open on my PC and is Lightweight. Whenever I open Element or any other client (Nheko, etc.) they all complain about each-other being unverified.

Clicking verify in any client does nothing. No popups in any other clients - doesn't ever seem to do anything. Sometimes Element will pop up a QR reader but there's no QR presented in the other clients. The UX around Matrix is a nightmare.

I am in the same boat. It is ridiculous and shows no signs of improving.