Hello everyone, a really great Rom.
I have installed on my Mate 9 (MHA L29 C432) as follows, back on Stock with HWOTA. Then 3 times wipe cache and factory reset with the stock recovery.
Then boot into the EMUI system.
In the developer options enable USB debugging.
Flash with Fastboot system.img and again wipe cache and factory reset (3 times) in the Stock Recovery. (In Germany we say: A lot helps a lot ?)
Boot and setup in Havoc.
Switch on USB debugging in the developer options again.
Then flash TWRP and Magisk 17.1
The only thing that doesn't work 100% for me is the Stock EMUI Camera.
I use a variant of the Gcam which works very well for me. (Except Video Recording !!!!!)
https://drive.google.com/file/d/1h4PnERMZc2dmbQAfgVNK28hulIefftDh/view?usp=drivesdk
Many thanks to the developer for your great work ?