Specific Mobs in Alex's Mobs are not spawning, but some are. For example, my savannas are covered in rhinos but no kangaroos, elephants, etc are spawning with them. My deserts will only spawn rain toads (only when raining, as intended), but no other desert mobs seem to be spawning. I haven't seen flies in general, & the list continues.

I am playing with 10 or so mods, but have tested with only Citadel & Alex's Mobs & the issue continues.
Not entirely a techy person, so unsure where I would even start in trying to fix this myself if I'm even able to. Help or generally looking into this would be greatly appreciated.