Villagers gone invisible

My house is near a village, I created some paths, put some job stands and beds in my house ; unenployed villagers came and claimed jobs as well as beds, they lived at my house for a few days, then went invisible. I still can hear them, but can't see or interact with them. I still can see some villagers in the village (at a distance), I can see the wandering trader, mobs, etc, but not the villagers that live in my house (where my respawn points are set and used frequently as they are my beds) .

Those unenployed villagers were created by me, in the village, after it had been emptied by a pillager attack (I guess), so I thought they may despawn, but it seems that they are not despawned but just invisible.

I played dozens of hours on a playstyle designed to profit from villagers living "with me", so it's very frustrating.

After many exiting-restarting the game, no change. Still invisible (but pretty noisy !).