Can anyone advise me please or just reassure me?

Goober my ABF giant (8mths old roughly) has not eaten in about 10 to 12 days.
He is normally very greedy but he is just refusing food, turns right away from it.
I can tell he has lost weight.
The odd thing is though he pooped in his water yesterday.
He has also shed recently.
There is NO food in his enclosure, as I normally feed him in a different tub or with tongs
while he sits in his bath.

Tonight he still will not eat.
I have tried him on crickets, locusts, slugs, roaches and his fave King worms.
How long can they go before it becomes a problem and something dangerous?

His tank is 27 degrees ambient temp, deep in his soil it is 29 to 31.
I know the temps are fine as the beeper has not gone off and I can see the readings.
He has a moist area, water and hide.
Day bulb if cold, moon bulb of a night.

I have no idea what to do.
Anyone?

Thank you for your time