This has only started happening recently, as in the past couple of days.
At random points after a fight my Gith Fighter (Tank build) gets stuck in combat mode and cannot use Mount, or interact with anything in the game that is not combat.
Every three or four seconds the character flips into normal mode and Mount icon lights up but immediately blacks out again for another few seconds and it's back into combat stance.
This applies in the Gear screen as "Unequip" flashes on briefly before going back to blacked out as well.
Sometimes jumping or blocking for a while alleviates this issue, but otherwise I have to find something to kill in the hope it resets, (which it does about 1/4 of the time) though I had 2 instances this morning where nothing would get me out of combat mode other than quitting the game and logging back in again.
I've been through the "Unequip" routine, and nothing has helped.