Sounds like delamination of the factory fitted screen protector.
If it is then you can ask a Samsung Service Centre if they'll replace it under the warranty.
They'll have to assess the phone first to see if this is the issue or not @olliehubb60
Daily Driver > Samsung Galaxy s²⁴ Ultra 512Gb ~ Titanium Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "
