Apparently there is a growing list of enemies in the game which are immune to bleeding, which from a lore standpoint, seems pretty reasonable, but to me seems questionnable at best from a gameplay mechanics perspective.
After all, looking at fire damage for comparison, even fire elementals are only slightly resistent against fire and we can more or less ignore that anyway because of passive boni that we just skill as an afterthought basically.
The only case of straight immunity against anything really is bleeds; stamina builds have a selective weakness in particular situations, where magicka builds have nothing like it. And even if there were comparable mobs, destro staff builds for instance could at least change their elements without too much effort, whereas stamina builds could... maybe trait an entirely new weapon line change to another weapon at best.