honestly it should heal that much baseline, shadows defensives are sorely lacking (not counting spamming 4 globals ahead of every oneshot mechanic) to not have great self heal
Not bugged!
This is why I roll shadow priest. Yes, sir!
For Evokers, I'm also seeing a bug where Breath of Eons is overwriting the original Ebon Might instead of adding to it. I've seen it multiple times on initial pulls in awakened raids.