So I have been trying to find the last bunny but I can't seem to, I have only been able to find 4 out of the 5 bunnies you are supposed to in the mountaints. When I go to the patron tower and use the "Finish quest" option it does nothing but reset the amount I have found and no new ones come in. Same with the "Reset quest" I can't seem to trigger the bunnies appearing. Id just like to know where they all spawn exactly or smt.

I hope you haven't saved after using the Patron tower or have a spare save file before doing so.

If you are sure the last one must be in the mountains you have to look very carefully. Sometimes they get close to trees and that will block them from your view. I recommend to first kill everything hostile moving around and then do it slowly.