I'm responding because you seem to be using the same machine I do and have roughly the same pressure requirements. I don't know the particulars of your apneas, but I am posting my stats just so you can be encouraged that there is a solution to your situation. I don't mean to try to brag about my numbers.
But, after years of trying, I finally got to where I was trying to get to, I think. Do you know how to hold down the knob and the right end of the long bar above and get into the menu and setting so that you can set your own numbers? I finally resorted to doing that and basically said "heck with the technicians at the DMEs". I'll just do it myself.
My sleep doctor retired and my DME co. was bought out by Lincare, so I was basically on my own. I also received help from a lot of kind folks on this forum. So you can have success.
I have found, out of all the masks I've used, that the Wisp has been the best for me. All the others hurt my nose and I woke up with ridges and soreness, but not with this mask. I've had some leaks, but not enough to be pervasive. But the main thing is that I've attained an AHI average of .86 and have averaged 6 hr 45 min of sleep per night. I've felt pretty good. (except for my bike wreck, with almost took me out of here a year ago)
I'm sure, with effort and persistence, that you will be able to do what I have done, mainly by myself. Good luck.