Environment:

• Java 1.20.2 Spigot server hosted by a friend (not my server)
• There are twenty villagers in an underground trading hall (no sky access). Each villager is inside of a minecart and each villager is next to an appropriate job site block (see screenshot "Trading Hall").
• There are no other claimed village blocks (no claimed blocks, no claimed beds, etc) within a ~120 block radius around this trading hall.
• The villagers were able to restock trades and give gifts for a long time, until somewhat recently.

Symptoms:

• Villagers do not work at job site blocks or restock trades. I have tried:
  • Logging on and off the server.
  • Sleeping in bed.
  • Switching dimensions.
  • Breaking and replacing jobsite blocks (I successfully see green particles).
• Villagers do not give gifts after a raid is defeated, nor do they give celebratory noises.
  • They also don't shoot fireworks, but as I understand this is Working As Intended since they have no sky access.

Steps to Replicate:

I'm somewhat uncertain what the cause is, and I unfortunately don't own the server otherwise I would clone a copy of the world so that I could test more thoroughly in creative. Here is what I suspect would be steps to replicate:

• Construct an underground trading hall with multiple villagers.
• The villagers were able to trade and restock earlier. I also defeated a raid earlier by myself, and I received Hero of the Village gifts as expected.
• The villagers stopped restocking and giving gifts after one particular raid, which was different from the previous solo raid:
  • There were multiple people online and participating during the raid. Three of us received "Hero of the Village" at the end of the raid.
  • During the raid, I placed and rang a bell from a place that was aboveground and close to the trading hall (~20 blocks away). The villager trading hall is underground and behind an iron door; this may mean that it is not possible for them to path find to the bell (maybe relevant?). See screenshot ("Iron Door")
• After this raid, all symptoms of the problem were present.
  • I started and defeated two more raids, and I also removed the bell that I placed. All symptoms still persisted after these raids.

Other Notes:

One of the resolutions I attempted was successful:

• Move the villager out of the trading hall to a place where they have sky access, then place a job site block next to them (note: villager is still in minecart):
  • If moved aboveground while they are still close to the trading hall (~20 blocks away), this resolution does not work.
  • If moved aboveground to a further location (~120 blocks away, to my villager breeder that has two claimed beds), this resolution consistently works.
    • I have applied this method to five of the twenty villagers. Each one now restocks as normal during the day, even after moving them back to the villager trade hall (and replacing the job site block). In the "Trading Hall" screenshot you can see three of those villagers working/restocking.

This makes me suspect that this issue relates to village centers/village subchunks.

If I am able to acquire a copy of the world from the host, I will attach it here.