Whats the problem here?

It's having a supreme issue with its head gear. Part or all of it. Try using a totally different rig or just swap out one piece at a time to find the culprit. It could be a sore mouth or dental issue, pinching or pressure applied in the wron. If the horse responds like this in ANY equipment on its head, then I'd look at this as a respect and retraining issue- the horse is not wanting to do what is asked of it and it needs to go back to something more basic and less demanding while reteaching it to go willingly and with respect for the aids.