Troll respawn. (Elex 2)

I just can’t understand how long the trolls will respawn, in particular, I need a mountain troll. Probably slept for 20 days, no trolls, for the life of me. One appeared near the bastion, but instead of a mountain one, a forest one. Version 1.03. Trolls are needed for stat boost potions, mountain troll for stamina. By the way, hippos respawn perfectly. Can someone explain what is happening with the respawn. Google didn't help.