our gliders will jump and climb on me, even groom the back of my head and neck all nice and stuff. but 2 of them, after about 1 hour or more of "tent" time will start to groom me harder. they will find spots on my arm and start to groom so hard they will open a wound and it will bleed. they will start to groom the back of my head and then start to hard groom. feels like they are pulling out my hair, hurts alot. so they are NOT biting me, might not be the same problem you are having, they are more like chewing on me. So far I can only move them away, gus comes back often and I have to keep moving him away. Gizmo isn't as bad and after I move him away he stays away longer.
so I dont really have a good answer, my best advice is to step back a little.
maybe stop tent time for a few weeks. sit near cage talk to them, feed them a few treats. open the door feed the treats, pet them if possible. don't let them bite you for awhile.
You dont have to be bonded to a glider to introduce them. we put connor in with a colony of 4. connor was just getting friendly with me, and out of the 4 one was a bit mean, and cupcake will bite also. the other 2 won't bite but still somewhat scared of us as we hadn't had them to long. after pouch swapping for awhile my wife did bathroom tub intros and it went great.