(note: Hearthstone application only looks weird because I am showing a none aspect ratio version of both my desktops 1 on screen in this video, the actual game look fine when you do this)
This is an issue I have had for a few months with Hearthstone a clear bug that does not get fixed, I CANNOT move the game to another Monitor. But yesterday I finally found a fix that allows it to work with no issue so I hope this video can help some people.
Usually for me hearthstone maximizes like crazy, which causes the game to crash when I try to move it to another display, sometimes it minimizes the game instead.
This hinders em from moving hearthstone around, same if I try to use the windows button.
Anyway, the fix is go to Window settings.
Display settings
Scale and Layout
Your recommend scale will likely be over 100%, probably 125% or 150%
Change this value to 100%.
After this you can move the Hearthstone application between your monitors again with no problem.
This issue is usually in window mode, where it will not at all allow to move in full screen mode.
To move it from full screen to another screen, first window mode it, so you can move the minimized window (with the 100% scale) and then full screen hearthstone on the other monitor.