Screen Replacement Looses Touch, Restarting it Fixes it

I Repair Phones as a hobby, sometimes people or friends ask me if i can repair their phones, etc. Last week i changed the LCD of an IPhone 8, I have repaired IPhones a lot of times without any problems, but this time, i changed the screen, all perfect, she took the phone and 5 days after she came saying that the touch screen wasnt working, all the phone worked, the screen displayed notifications and all but the touch wasnt working. I took the phone, reconnected the screen and.. it worked again. She took the phone again and other 4 days after same thing. I replaced the screen again, i always purchase on ebay, and i have never had problems. Another screen and 2 days after, same problem.. this time I haven't even disconnected the screen, only the battery connection, restarted the phone and… it worked again. I think even with a forced restartd (volume and power button etc) it would work… any ideas?