I've made a new build yesterday with these components :
Core I3 9100
Gigabyte z390 I AORUS PRO WIFI
Crucial DDR4 32 Go (2 x 16 Go) 2400 MHz CL17 DR X8
Samsung SSD 860 EVO 500 Go
(No graphic card, I don't need it)
At the beginning, I had problems to shutdown, but I've fix it...
I spent more than 30 hours trying to find a solution, but no way.
I've already built 9 Hackintoshes in the last ten years and I've never had such problems.
However, I bought this hardware according to the Tonymac's Buyer's Guide. I thought I could trust it (usually I could).
Well, I finally managed to make it work.
It was my USB extension cord that was too old (USB2 only, I think?).
Put my USB stick directly in USB ports,
re-done the RehabMan guide method, and it worked.
Thanks anyway, and sorry for the inconvenience.
I've build this hack three years ago...