Minecraft villager Paper MC 1.16.5 is not accepting a job?

I've made a shop full of librarians. Now I have 7 where everything worked perfectly. Now it doesn't work at all or only rarely for all the others that I add to accept the job.

If you already traded with the villager, the job will be locked

No one woks not even if they were born 2 hours ago and never saw anything except for cobblestone a Bed and other villagers. Straight from the breeding section as seen on the second pic.

Help mineos my create server