Even with screen protectors and stuff, that should work.
Try this
1) make a nand backup of your phone, in Recovery.
2) use the RUU to re-flash your phone to 100% stock.
3) *228 to activate because it will probably make you again
4) make a phone call and see if the problem exists.
If it exists, then take your phone to Verizon, and show them how it doesn't work.
It's okay if the phone takes a volume button push to come back ON. But it should be shutting OFF when you put your face up to it, on a phone call. If it's not doing this, take it to Verizon.
If the problem ISN'T there, then re-root your phone, get your Amon-RA recovery back on there, and restore your nand backup.
Then, I suggest, re-flashing xtrSense/xtrROM.
Those ROMs didn't touch ANYTHING in how the phone talks to those sensors, and has fully 100% stock functionality in that area. Should work.
A wipe/wipe, and reflash is the best, if the RUU worked.