A villager named with a nametag will lose their name whenever they change profession, which happens alot in my 48-villager free range village with a limited amount of workstations.
I know for certain that the villagers aren't dying. I have list of all the named villagers, and the total villager count. The villager count always stays at 48 (I have built up a large village) but the named ones disappear the moment an unemployed villager steals a named villagers station, and the named one becomes unemployed or changes profession.
However, there is an exception. I have noticed that when an unemployed villager is named, they keep that name when picking their first job. It only seems like the name disappears when they switch from one profession to another.
However, this phenomenon only seems to occur on one of my worlds, created in the very first version of 1.14. I tried to recreate the problem in a new world but couldn't, although I didn't do that in a village.
Comments 2
Recently on my survival world all of the villagers ~42 (I'm still breeding more) have lost their names. They are locked into cells where they can't die, move, or change professions . I had them in there for a while and their names were staying fine but then after using a raid farm and coming back with hero of the village, they somehow lost their names. I renamed them all and they lost their names again within a few hours, again this was after trading with them while hero of the village was active. I haven't been able to reproduce the bug on a creative test world.
Are you sure it was changing professions that caused this bug in your case? I was thinking it might be related to hero of the village.
I'm unable to reproduce this in 1.14.4.