iPhone 8 Plus touches go crazy (ghost or no) after screen replacement

I have iPhone 8 Plus with broken screen. Have changed it to eTradeSupply screen, after one day the screen gone crazy - there is no touches at times, ghost touches at times, sometime all is good. Original broken (glass) screen was working good. I have tried hard reset and etc. Obvious advice everywhere is to change screen to another one, however there is a little twist -> the screen is perfectly working with out any problems if you open the phone (so the screen part is not closed/connected with the rest of the phone), looks like the flex cable might be a problem (bending?) or is anything else may cause that? Any thoughts?