Computer screen resolution changed while playing EQ

[jtmize]

I use a surface pro 4 and accidentally tilted it while playing so that the screen went vertical for a second. After tilting back to horizontal, EQ changed the resolution of my computer. I changed it back to the recommended settings in display settings, but now I have black bars on the sides about an inch thick on each side, limiting how much of my screen is used.

Anyone have this issue? It's quite annoying and I'm not sure how to fix. I've tried all the different screen resolutions in the settings.

Appreciate any help!