Touch screen stops working randomly

Hello,

I really hope someone could help me.

My phone's touchscreen is becoming unresponsive at random times but mostly if the phone is not being used and I'm moving(in my pocket). The display works fine, if I am pressing lock twice, for example, the camera app pops but I am not able to press the caption button.
This issue is resolved if I restart the phone (volume down and lock button), but after a few minutes it becomes unresponsive again.
Also I noticed that the battery drains way faster.
This is how I tried so far to solve the issue:
-delete recent downloaded apps
-start the phone in safe mode
-reset factory the phone

This issue started at the end of quite very high altitude, not sure if this could be related.

Help would be really much appreciated, currently backpacking and don't afford a new phone or spending loads of money on repairing.

Thank you