I think some faces just don’t work with the default interface. I had the same problem as you with the super ultrawide. Couldn’t get more than around 120 FOV. I started using small FOV settings by default because it wouldn’t make any difference.
Then I received the OLED module and I couldn’t make more than 105 FOV. Trying the silk mask, the default thin mask, the studio form mask and another cheap one bought online…
That’s when it hit me. I took the face interface off the headset and when pushing my face closer to the lenses, to the point my eyelashes would almost touch the lenses, I got to experience the full FOV on both modules.
The reality is the default face interface doesn’t fit all faces. In my case my cheekbones prevent me from getting close enough.
My current solution: I cut the foam from the bottom of the face mask foam and now I can experience the full FOV while loosing a bit of comfort.
Better solution: modify the 3D model of the face mask provided by Pimax and print a custom version. A redditor will help me with that. If I can get my face 3-5 mm closer to the lenses that will solve it.
I hope Pimax will provide different variations of the facial interface in the future.