Not sure what triggers it, but it can go in an infinite cooldown loop now.
Additional info: it persists even after dismounting or using waypoints. Most likely goes away with map change but have not tried (yes, just tried it).
Just to clarify what exactly I mean by infinite cooldown loop:
Superior battle maul goes on cooldown..3...2....1 - this is where you are supposed to be able to use it again, but the moment it resets, it goes immediately to 3..2..1.. rinse&repeat forever.