I purchased a Comfort Gel nose mask and had great difficulty in adjusting it to avoid leaking in various positions. I finally found the answer in a simple plastic bag wire tie. The tie was wound around the upper and lower straps pulling them together in the center at the back of the head. It seems to allow the mask to pivot better on an "up and down" head motion (as in an affirmative head shake). I find that the tension or tightness of top and bottom straps is more evenly distributed with the two straps wired together.

Seems like my comfort gel masks kind of soften up after a few nights of use and that seems to help with leaks. Also remember that there is an angle adjustment on the mask as well, so you might just need to tweak the angle closer to the area that is leaking.

Also, I wonder if they gave you the wrong head gear. The top and bottom straps are attached to each other on my headgear so they cant get too far apart..

Its similar to this:

Yes I have the same mask and headgear. I put the tie at the middle on the back and tie the upper and lower straps together. I don't know what makes it better but it stops leaks that i used to have when tipping my head.

if you do their resizing procedure it will fit even better