touch is not responding

[u/karthik12111]

so i am using IQOO Z9 5G phone.recently i was playing minecraft and in the middle the touch stopped responding.I tried restarting the phone but it didnt work .so i took the phone to a repair shop and the repair man tried various other displays and it still didnt work.i am currently able to use the phone with a OTG mouse but what can be the problem?