Touch screen becomes unresponsive after applying pressure glass replac

After performing a front glass replacement on my friends phone, the touch screen becomes unresponsive after applying a decent amount of pressure to the screen.

After applying the pressure, nothing responds, whether it be the screen itself or the touch buttons. The main button works fine.

I followed the guides on here perfectly, I did discolour the screen by applying a little too much heat but stopped as soon as I noticed, do you think that will be related? It's in the top right hand corner.

Thanks!