I have a 1.19 world with some mods like byg and bop, exploring a lot i only found 2 mobs.
I made an other world but in creative, and a saw only one mob more and i explore over 10 diferent biomes .
Im not sure if it's normal or if it's a problem.
What can i do to solve it?

I have been basically having the same problem, for some reason the mobs wont spawn.

I'm having the same issue in a 1.19 world. I've only seen 2 animals so far

delete the config

then reopen forge it worked for me :)