To anyone still having this bug go ahead and press your (Left ALT) key on your keyboard about 4-5 times. This solution works for me whenever this bug occurs. Cheers all and hope this helps in the future! :-)
I've been playing WoW since the end of BC and I've never had anything like this before until today. It happened to my mage as soon as we started the FH+9 and exiting out of the game and logging back worked. It was very frustrating. Then my dps meter bugged for about 5 minutes. Whatever the cause is please find a solution as this happening in raids, high lvl m+ keys and in pvp is a big no no...
This is the second time it's happened to me, ever, and both have been during BFA. This time it was during an island expedition, and I got booted out for my inability to hit things. Thanks Blizz. Great coding you've got there. Can't even fix a 7 year old bug.