I had a similar issue on my single player world, however I didn’t leave the area or change the mobs’ positions since before this began happening. Also, in the case of villagers, their other mechanics aside from spawning and despawning aren’t working properly. Particularly, the villagers I cure from zombie spawners are permanently locked to their trades and profession by default, (again, this didn’t happen before the last update)
I had a similar issue on my single player world, however I didn’t leave the area or change the mobs’ positions since before this began happening. Also, in the case of villagers, their other mechanics aside from spawning and despawning aren’t working properly. Particularly, the villagers I cure from zombie spawners are permanently locked to their trades and profession by default, (again, this didn’t happen before the last update)