Ocelot

After testing I found out that villagers seem to lose their "minecraft:job_site" memory under certain conditions. One of those conditions seems to be exhausing their trade option at night.

I created an enclosed room with a bed and brewing stand in center. Created a villager in creative mode and vaited until he claims the stand. Trade zombie flesh at day until trade is locked → restocked normally, memories intact, RestocksToday is 1.

Awakened him at night and traded until zombie meat trade is blocked again. Waited about 10 minutes →  "minecraft:job_site" memory is gone from his entity data, RestocksToday is still 1.

Example of memories of affected villager: 

Brain: {
  memories: {
    "minecraft:home": {
      value: {
        pos: [I; 15, 254, 2823], 
        dimension: "minecraft:overworld"
      }
    }, 
    "minecraft:last_slept": {
      value: 44568368L
    }, 
    "minecraft:last_woken": {
      value: 44568601L
    }, 
    "minecraft:last_worked_at_poi": {
      value: 44561922L
    }
  }
}