If he burmated at about his age he would die. He's probably about 2-4 months old.
Relocation stress is definitely one of the causes in him not eating, setup issues would be the second cause. Possibly more depending on how his health is and a few other things.
Make sure you have at the very least a 20 gallon for him, 10 gallons are unsuitable as they can not provide 3 temperature zones that a dragon needs.
Those 3 temperature zones being the basking spot(s), warm side and then cool side.
Basking spot ranging from 100-110.
Warm side 88-95.
And cool side being 70-85.
Night time temps no lower than 65 and no higher than 85.
If it gets to low you can use a ceramic heat emitter (CHE). You can NOT use red/purple/black/green/blue lights on beardies, they see in color just like us (plus more as they have around 4 color receptors and we only have around 3) so having a bright light on them during the night can keep them up.
Also just so you know once he turns 6 months he'll need at least a 40 or 50 gallon and then when hes around 12 months he should be moved into a 75 at minimum. Although if necessary they can be kept in the below minimum of a 40 or 50 gallon for a few years however theres no real way around not providing them the exact minimum.
Some people say they can be in 40 or 50 gallons their whole 15-20 years of life however thats just wrong and in my opinion a bit stupid. I mean a 18-24 inch lizard living its life in a tank where it only has maybe a foot of space left? Pretty dumb in my opinion, at least a 75 gallon provides about 2-3 feet of space to exercise by roaming around and also provides about 21 inches of height for them to climb if you provide logs and hammocks. Which you should as they are semi aboral and love to climb.
Anyway now for some questions,
What is your substrate? (Tile, sand, calci sand, paper towels ect)
What are your temperatures?
What are you monitoring your temperatures with?
What are you trying to feed him (tell me about both greens and insects)
What are you using to dust his insects (Calcium without d3, calcium with d3, multivitamin ect)
What is your dusting plans? (5x a week calcium, 2x a week calcium, 2x a week multivitamin ect)
What is his tank size right now?
Is he housed with any other beardies?
What UVB brand did you purchase (zoomed/reptisun, exo terra, arcadia ect)
Is your UVB a coil/compact, a MVB, or a tube light?
How far is the UVB from the basking spot?
Is the UVB a t5 or a t8?
Is it a 5.0, 10.0, 12% or 14%?
Is the UVB mounted inside or on a screen?
Also stress marks aren't caused by stress, its natural patterning that just happens, usually when basking. Darker colors absorb more heat basically so they darken to heat up or try to.
Really have no idea how that myth began.