I have noticed my villagers would lose their jobs even though I would trade with them.

I started to notice this when I have a trading hall full of villagers, they aren't able to move from their spot, but I notice that they were all trying to take each others jobs for an odd reason. After this kept happening they would lose their job or switch to a new type of villager even though they had been fully maxed out or traded with.
Pc,  xbox, mobile, switch, bedrock edition.