Sounds like the adhesive isn't going through the proper cure process. I know the screen is laminated sheets that are glued together, so this sounds like it may very well be the case. This is the kind of junk you see when either the assemblers don't properly follow the process, or corners are cut to get more devices out the door. Being in manufacturing you see the most unbelievable mistakes. Most of our products go through vibration testing. On some of them, the IC's are prone to either being ejected from the board - pads with them - or having their leads break a the device case when they are vibrated. To prevent this, the devices can be bonded to the board with bonding material. We had one board where the bonding material was applied to the top of one of the IC's but not down the side and on the board, where it needs to be to keep it from vibrating, and the device had numerous leads sheared at the case after vibration. Our ME's just go nuts wondering what the operator who bonded the device was thinking.
If you believe you may have a curing issue, use a blower drier on warm for few minutes and see if the issue starts to go away. Just don't get the battery too hot.