Ive been testing on single biome worlds and normal generation for mobs to spawn. Im playing with optifine, citadel, and alexs mobs. Barely any mobs are spawning in their biomes, and bears spawn in every single biome as well. Definitely a huge glitch so fix as soon as possible.

I've done a bit more looking into this bug, and it seems the main mobs that spawn are mobs after mod update 1.19.0 and tons of bears. I don't know ho to fix, and I've tried changing many settings in-game, but I have no clue why this is happening.