I've had this same problem. Though I've seen it last patch too. It seemed to happen whenever the terrain wasn't fully loaded (or won't load, which is something that happens very often now). Might be a threading problem, because from what I've seen the game ignores any kind of input to stop it. Also, the fact that it always happens in a situation with network lag makes me think the network thread is the problem. I've longed guessed the game works in this priority network -> draw -> input. Maybe it's true.
On a side note, it allows you to do some impossible things like sprint and attack...ZOS should look into it because its only a matter of time before someone finds a way to exploit it. You still get stam back from certain actions, just not stam regen.
I really can't imagine what would be possible if someone had maximum movement speed, purposely triggered this bug, and were "skilled" enough to use it...
Since the mid year mayhem event the frequency of this occuring has increased by roughly 5000% percent. In my 3 man group at least one of us has it on us at any one time. Makes the game/ small scale basically impossible.
It is geting really old dealing with the flaws in this game.
I got stuck in sprint several times yesterday. On top of that, it wasn't even greying out the skill bar, so there was no visual queue that you couldn't use your skills. Very easy to get killed while this is happening since you can't do anything until you've figured out what's going on.
That's on top of things not triggering CC immunity and having to break CC 2-3 times to get out of it.
Agrippa Invisus / Indominus / Inprimis / Inviolatus
DragonKnight / Templar / Warden / Sorcerer - Vagabond
Once a General, now a Citizen
Former Emperor of Bloodthorn and Vivec
For Sweetrolls! FOR FIMIAN!
This is a pretty well known and very commom bug. It happens to me multiple times a day and it's really annyoing, kinda gamebreaking in my opinion with how much it happens.
So many times I get someone to execute range then can't press anything so they get time to heal up. Or I'm being chased by loads of players and can't press any heals or buffs. It has lost me so many fights.