Guild Wars 2

Hello I’m new to ranger and I got a question!

I’m going for a beastmaster build and I tried to combine three healing skills for my pet, natural regen (grandmaster trait), singet of the wild (utility) and canavrous appetite (trait) but when I tried it out agianst the class dummies in the mist it’s only the utility heal that works.

Is this intended?

The skill wont activate if its health is a full.