Tuning and Altissimo

Recently I played with a band and had to pull way out to be in tune, sounded almost like they all were tuned low. I am in tune (with a tuner) with my mouthpiece covering a bit less than 3/4 of the cork.

Anyways... The real question in this post... When I had my mouthpiece pulled out so much, my altissimo was HORRIDLY unresponsive from G3-B4. That's unfortunately my most effective range in altissimo, I don't play higher than D4 cause it just sounds like YUCK.

This happens and is most noticable on my Tenor setup with either mouthpiece. Has anyone ever experienced this? What should I do to correct this, as I feel that I should be able to play my "full range" comfortably wherever the mouthpiece is on the horn?

Thanks!