I'm so so worried because this is not my tablet, a friend lent me theirs for a week and I seem to have broken it, but it only happens on one computer so I can't tell?

It was working fine two hours ago and was able to create smooth lines on any correction level, no lag, etc. Then my apartment fire alarm building went off and we all had to evacuate, and I didn't want to leave my friend's expensive tablet here in case there was a real fire, so I put it in a tote bag with my small light weight laptop and the pen. I was gentle when placing it and held the bag the whole time, it didn't knock against walls/floors/etc.

However when I got back (no real fire) and plugged it into my computer, it started acting like this after maybe five minutes of drawing. Curved lines act like a bunch of connecting straight lines instead and sometimes it will lag significantly and the line will just "skip" to wherever the cursor is at that moment. The black lines were done with a watercolor brush that's already really slow but never this bad, the blue lines were done with the most basic "pen" setting and you can see it's better but still not a real curved/smooth line.

I restarted my computer, reinstalled the driver, etc and nothing seems to fix it. I use medibang paint and don't have any other programs but I opened some web drawing pages and it seemed to be fine there, but it's hard to tell because those pages aren't an exact match quality and features wise. I then installed Medibang on my sister's computer and tried this tablet on there, and it worked perfectly fine. I also tried my old tablet which is much much worse, and it seemed to do fine on my sister's computer and still be a little glitchy on mine, though not as bad as the Artist 12 Pro was. However it's a really shitty tablet so it's hard to tell, and the Artist 12 Pro acting that much worse has me worried.

I am so confused about it the issue is my tablet, my laptop, or something else. Has anyone encountered something like this before? I also tried it on various stabilization/correction settings and none of them made the issue any better or worse. If I broke my friend's tablet I will definitely pay to replace it, but I'm really hoping I didn't because I would be so embarrassed and feel horrible. They lent me theirs so I could see if I wanted to save up for my own but now I think I might have to give up on that so I can replace this one.

Sorry for the long post, I just feel awful and I'm hoping there's something I'm missing here : /

Please help! Artist 12 pro creating jagged curves & lagging horribly only on one computer