I have only noticed since the 1.18.2 update but this could've happened from 1.18.1; I initially noticed that my minecarts disappeared in my auto smelter, the next day when going to trad I found that 90% of all my villagers despawned as well. This seems to be completely random/ possibly based on what chunk they're in as my auto-farms still work fine and I know nothing is wrong with my villager trading hall as it's been working well for over a year now (incidentally now lost my rare melon slice trades which you can't get anymore ).

Would love to see this addressed soon as I'm cautious with setting up trades in case this happens again.