Villagers in a village can spawn without profession when the village is generated

The bug

Villagers in a village can spawn without profession when the village is generated.

Even after that, they can not find work.

How to reproduce

1. Go to a village (You can use the locate command)

2. You will see that the villagers do not have a profession despite the fact that there are blocks of profession around

Example

Here is an example in video: