How To - PPK Processing with RTKLib (Phantom 4 RTK)

Hey, i’m struggling with processing observation file from P4 RTK in RTKLIB. I hope someone could have a look and share some thoughts about possible issue.

Most of the time I did not get solution, when i decrease elevation mask to 0 then eventually 8% of observation get Q=1, 91% Q=2.

I used following settings:

I also share link to my observation files from drone, nearest OS_net station and navigation file.
https://drive.google.com/drive/folders/1_-4NaFBSYohRuRPjzdcmVC3OGac58BqM?usp=sharing

Thanks, Mag.