Mobs not spawning.

Mobs are not spawning in survival world after updating to newest snapshot from latest release. Cycled difficulties to no avail.

 

Update: Spawners work, drowners near underwater structeres as well. And nether mobs. Seems to be only hostile mobs in overworld.

 

New worlds aren't affected, seems to be due to an old world (which was started with 1.13) updating to new snap