It's not all the time, and it only started last weekend. When it does this, it looks like it's ticking up, but doesn't. The blue bar surges up a bit, then drops back, as if I were under a debuff that took away exactly what I was given. I'm not. No debuff lasts 15 minutes or more, and nothing shows on my character sheet under active effects. I spent that long looking for an answer the second time I noticed it happening. Toggle away, google, toggle back to check, move to keep connection alive, toggle way, google, repeat.
I can't tell if it's just Magicka or health and stamina too, because I'm a Mag-Templar and my attacks heal me. I rarely use any stamina to know if it recovers or not.
Logging off and back on doesn't help. Going through another combat doesn't help. It's not even ticking up like it should be in combat.
Drinking a potion will make my mag go up by the amount it's supposed to, but the extra buff to recover doesn't change anything. Once it's gone up by the amount the pot gives, it goes back to the little surges again.
I can't figure out what triggers this bug, or what triggers it to start up again. Yesterday, using a store-scroll of xp boost got it working again, but a store-pot of recovery didn't later. Or it could have just been the timing.
And yes, I've reported this bug in-game. I don't know how to get a video of what's happening, sorry.