The bug

The more workstations (points of interest / POIs / job site blocks / job sites) are near a villager, the longer it will take it to get a job. This also is the case if the villager cannot pathfind to most of the nearby POIs.

To reproduce

1. Spawn a villager in an enclosed space
2. Place a lectern near the villager
   → The villager immediately gets the job
3. Break the lectern
4. Go outside of the enclosed space
5. Run /fill ~ ~ ~ ~15 ~15 ~15 minecraft:smithing_table
6. Place a lectern near the villager
   → The villager takes ages to get a job
7. Remove all the smithing tables again
   → Now the villager immediately got a job again

Video

https://youtu.be/kahunXXCS3s