No Fullscreen on Samsung S20+

I have had my Samsung S20+ for over a year, and I can’t play Hearthstone in fullscreen on it. There is a black bar on one side of the screen. I have always played Hearthstone on Samsung Devices and this is the first time that I am having this issue.

I do not have this issue with Magic the Gathering Arena or any other games.

I also cannot use the force fullscreen function as I can with other applications. No matter what I do this quarter inch black bar remains.

Does anyone have a work around?

I really sucks.