@matana my first thought was that it was a software issue because the key that was broken would switch around all the time and it worked without issue on linux, although I don't use Linux much so I can't really confirm that. I tried replacing drivers and stuff but that didn't work so that's why I cleaned it.
But I don't see how a hardware problem would cause backspace to not work unless text is highlighted. That's fucking weird.
@matana ohhh I think I might have a theory. Backspace might be pressing another key so it presses that key and immediately erases it. I'll have to mess around with it some more.
It's funny that I can fix a GPU and paint an entire guitar controller while fixing its connection issues but can't clean a keyboard apparently lol.
