A user with the same problem posted under a different heading, that he was able to fix the issue by uninstalling the One UI Home app on his phone. Go to Settings-Apps-One UI Home-Three Dots in the upper right hand corner-Uninstall updates. I also hit "Force Stop". After you do this you lose a lot of Home screen functionality. The app is needed, so I rebooted my phone and updated the One UI Home App. This seemed to work for me so far. I am also pleased that the issue could be related to a software bug vs. a hardware issue where the screen would have to be replaced. If anyone tries and plays around with the One UI Home app and is successful in solving the issue please post. There are a lot of post with this issue and this could be the "solved" answer.
AUsum, sorry you are having issues with the Flip 3. You are not alone. Just to update, the uninstalling the UI Home solution eventually did NOT work after all. I am a United States user and I found a UbreakiFix store location that replaced the front screen under warranty and I then traded in my phone with Samsung for the Galaxy Flip 4. Pretty much the same phone but the fold feels stronger. So far I have not read about anyone have any issues. Hopefully Samsung improved on the issue. When the phone was first released Samsung US was giving a generous trade in amount. Samsung is aware of the issue. Try calling and request a warranty repair. You have to be persistent and try and get Samsung to replace the screen for free. Depending on which country you are from they may or may not fix it. You may have to call several different Customer Service Representatives because they all give different answers, solutions and responses to the issue. Good luck.
I found the solution to this problem after Samsung refusing to inspect the problem but try really hard to void your warranty by FINDING a scratch. Anyway, I found out it was a RAM issue for my case, so I screenshot the list while I clear memory (RAM) for unused apps. What worked for mine is the "Meta Services", which allegedly is for Facebook. After disable this in the setting-->app, it works perfectly.
But, will never buy anything from Samsung after their terrible service and bad approach to solve issues - by FINDING a scratch and waiving your warranty! Problem solved for them!