Can't move Hearthstone window to a different screen

Since i didn’t get any help from support:

I want to (and once have been able to) sometimes play Hearthstone on my projector that’s hooked up to my PC. Now, it is scaled to 125% to make it readable from the couch.
Lately, when i moved the the windows to the screen, after a few seconds it started rescaling itself up and up and the window got bigger and bigger until the game crashed.

I used to be able to do this without problems maybe 2 years ago, but now i can’t.

Anyone has/had a similar problem?