charging causing issues to touchscreen

So lately I've had the problem of my phone's touch display malfunctioning when connected to a charger (This includes when it's 100% and charging)

Say this:

I'm typing a message in Whatsapp, and when I press the E button on the keyboard it spaces out and presses something else instead, (not just typing, but swiping, scrolling, anything that requires touch input (which is basically everything))

I think I might be able to fix this myself, but I'd need to know which part it would be, does anyone know which part to replace if that's the problem?

Note: this only happens when I'm in using an app or doing anything, when I'm on the lock or home screen it works perfectly fine, however even in the notification centre it causes this issue.

Second Note: Mostly the bottom area gets affected the most