Is this print reslut normal

i just got a formlabs fuse 1+30W setup
nylon11CF, freash powder and nitrogen

the print we got all got result like the picture show
the “UP” surface always have the edge area tilt up , and lower section “radius” effect
the print current working under no nitrogen condition
custom service said : it is normal and nitrogen won’t help
one of mone friten running printer farm said : it will gone with notrogen
but i think i would better ask more brfore set conclusion and buy the notrogen thing
nay hlep wpuld be appreciate
thanks