I've been having an issue with my Fold 4 recently where the cover screen will randomly stop recognizing touch input. The display still works fine, no flickering or odd artifacts, just the touch won't work.
It comes and goes. Sometimes it will work fine for weeks without issue, other times it will stop working for days on end, or even be in and out multiple times in a day. It seems to be software related and not hardware. Clearing the cache used to be a reliable fix, but at some point it stopped being a solution and now it's totally random whether it will help or not.
Restarting the phone or booting into Safe Mode has no effect. It always persists between restarts if the cache isn't cleared. To make things stranger, if I activate the rear camera selfie mode in the camera app, I am able to use the front touch screen in the camera app even when it isn't working otherwise. If I try to return to the launcher on the cover screen from the selfie camera with the phone still unfolded (so the internal display doesn't activate), touch input stops working again as soon as the camera app is closed.
I am completely stumped here. If it was an issue with an app that I installed, things should work fine in Safe Mode. If it was a hardware problem, I assume it wouldn't suddenly start working when using the cover screen for taking rear camera selfies and stop again immediately after leaving the camera. I can only guess that there's something wrong with a preinstalled app or whatever software Samsung wrote to control the multiple displays.
I'll take any suggestions at all if anyone has them...
Update for anyone else who might see this: I took the phone to BestBuy to get it repaired, but when they checked the IMEI, they told me it still had a few weeks of warranty left on it. So, after sending the phone off to Samsung for warranty repair, they just replaced it with a new one.