My iPad mini 4 gen have some GLITCHES!!?

After i lock the iPad. And then wake the screen or unlock it SOMETIMES the screen start Glitching and show some lines and all of that for a few seconds and before settle down the screen light become or back to the level where it is before and look like nothing happen!!!.

i have this issue for i while. About few months if not around the year. I can't remember exactly when start it!!

NOTE: the iPad current situation is bad. The battery now about 50% in the health. And i think it's a little swollen. It doesn show but i think i fell it sone time. And the performance is low. I can't even game and watch youtube above 1080p..!

so my question is:

is it software or hardware issue!?

(( unfortunaly i can't upload the video i take for the issue and when i take screen shot from the video it becaome large that the system here doesn’t accept it ))