Excellent. thanks for the info.
Actually I did a port from another TWRP that was on 3.1.1 that was easier. Well not a real contributor. My knowledge is so low. I am learning every time a lot when I try something new. Most time it happens that I have to recover my TWRP image
I am not a developer like the other professional on XDA, but maybe in ten years I am good enough.
I also had this experience that the recovery was overwritten after a new flash and reverted to original one. Looks like a script doing that, as Blackview uses verified images. But flashing then only the TWRP recovery again after normal boot made it permanent (on MM)
I also use Magisk (still on MM), it's the best indeed.
What I do on this phone, I flash the ROM, boot it up, shut it down and flash the recovery only. That worked best for me.
Thanks for your feedback.
PS: In another forum I had a guy who had a brand new P2 and the ROM was completely different. Looks like some delivered phones were completely mixed up.