In frozen biomes, orcas and seals are spawning in abundance but no pandas. When I disable this mod, they return. I don't have any other mods that alter mob spawning in these biomes. Same with some other vanilla mobs in biomes where moose and raccoons spawn.

I've tried messing with the configs but it seems to have minimal impact. (1 polar bear group spawns instead of 0 even when I set seal spawn weight to like, 5.)

Any update on this? It's impossible to find turtles anymore.

Can confirm this is still happening in 1.20.1. Even after hours of searching they were impossible to find until I turned off the mod.

I can confirm.
Turtles are being yeeted by Seals. I tested it with FTB Endevour after removing all mods except Alex and Citadel.