Around 1½ years ago I've sent my device for servicing because my power button was stiff.
Since last few months, the back panel adhesive is loosen up and the right air trigger is also acting up due to open back panel from the lower right edge.
I'm someone who puts a case and remove rarely just to clean off the dust and have a good record not dropping or sitting on the phone.
Asus I need it fixed, loosen glue is not something that I would expect after some time of servicing. It just shows poor servicing from your service centers.