Touchscreen reacts strangely after battery change.

Hi,

my Tablet wasnt turning on or charging for months now, so I finally got the spare parts and changed the battery according to this pages guide. So far so good, turns on and works, BUT the touchscreen now behaves funnily. I can not swipe, I can't "reach" certain areas and touching is overall inaccurate. Did I maybe damage it during the swap? Could one of the ribbon cables not be properly reattached? Or did I screw in one of the screws too much? Did anyone mage a similar experience and could help me out?

Thanks for pointing me in the right direction!