Edit: Nevermind I'm pretty sure its me.

So this game of subeku I'm playing and using the "Check" Feature on seems to have some problems with it. I'm at my college playing during a break between classes, so I don't know if I'll be able to reply right away, but I wanted to see if anyone else has noticed this or if it's a known bug (I skimmed but didn't see it anywhere)
I have screenshots, but again, I'm just on a quick break and can't quite figure out how to post them yet. Basically, the only option left for a number in a row is already in the box in another location. And in another box, the number I need for that box is already in the row for another location. It's saying everything looks good, no mistakes. So, I'm not sure if I'm the problem or if this is known about etc