My google pixel screen keeps going black after being replaced

My Pixel 4 screen keeps randomly going black, and usually comes back on by pressing down really hard on the screen. I brought this a local repair shop, and uBreakiFix. The local repair shop replaced the screen and then suggested pressing down on it will fix it, while uBreakiFix just said they couldn't fix it. Recently I haven't been able to make the phone turn back on by pressing down on it. The local repair shop also said something about an fpc connector? No idea if that will help.