AN Absorption fridge requires:
Proper Installation by RV Mfg.-----many times this is NOT done correctly
Sufficient air flow (Draft)-------this can be enhanced by using fan(s) and baffles
Being Level..........Atwood uses a TILT Sensor
Sufficient heat source
I suspect the first two items are lacking on your Atwood Fridge
HERE is an Installation/Operating Manual for your fridge.
Pg. 3 depicts proper installation/clearances/baffles for Atwood Fridge in a slide out. Fan is used.
IF not in compliance with Atwood Requirements....fridge will never get as cold as it should.
Remove upper/lower fridge vents and have a look.......minimal clearance, baffles, and fan.
IF not correct....warranty item!!!