Eraser tool acting strange [ Photoshop 2020 ]

Hey all,

I recently upgraded from PS 2018 to 2020 and am having some issues. I've managed to sort most out including the ridiculous transform changes, but one has me stumped. I started doing some basic drawing and needed to use the eraser tool, but noticed that nothing was erased. I undid the use of the eraser and noticed that my lines were darker, almost as if there was a dupliate layer below it. I only had two layers active, the background layer, and the new one I created to draw on.

I hid my drawing layer and noticed that somehow there was a "copy" of my drawing on the background. Out of curiosity I hid the background layer and then made it visible again only for the "copy" to not be there. Making the drawing layer visible revealed my original piece, missing the parts I tried erasing. I've been over settings, tried different things but still cannot fix this issue.

A bit more info, I've noticed that if I zoom in the "copy" disappears, but when zoom out (either with ctrl/- or ctrl/0) it shows up again. I've never had this issue with my older version, and honestly it's really starting to piss me off.

Any help or info would be greatly appreciated.