When I open nheko, a dialog box says "Activate encryption"; "to make this device trusted {blah blah blah}" with a big "Verify" button. Pressing it does the same as closing the dialog, so a whole lot of nothing. Same right now. I did try logging out and back in on different devices, back then only though.

I don't use nheko, I think it should have shown a menu saying something like "waiting to accept verification request". thats what other clients do.

did you have any other client opened on another device when you pressed verify?