by generating a villager without exchanges (and with profession and level) and unload those chuncks(see if they are in the spawnChunks) or relogue, this generates new exchanges

commands to summon villager example:

summon minecraft:villager ~ ~1 ~ {Offers:

,VillagerData:{profession:"minecraft:farmer",level:2}}

summon minecraft:villager ~ ~1 ~ {Offers:{},VillagerData:{profession:"minecraft:farmer",level:2}}