All villagers have trading xp so the trade can’t be changed.
MCPE-194062
Village xp trading bug
Resolved
Cannot Reproduce
0
MCPE-194062
All villagers have trading xp so the trade can’t be changed.
The villagers do not have experience. Gray on the experience bar shows how much the highlighted trade will give. Blue shows how much the villager has.
To change a villager's profession, you need to place a workstation block and a bed.