aorus master z790x pcie 5.0 16x freeze my 4090 HELP

[fenice19]

hi i've assembled a new pc but when i install my gigabyte 4090 master into pcie 5.0 16x slot window freeze after 1 or two min.
the only way to solve the bug is downgrade  it to 8x using pcie bifurcation 8x8 ( there is an other option to downgrade by bios to 8x ? i see nothing in bios).
i.m trying to force 8x installing a m2 drive to m2c slot (the upper one  that share the lanes with pcie5 slot).
activating  pcie bifurcation during cold boot system shutdown after 10 sec and reboot the all work fine.
someone can help me ?

[dmdilks]

By what I'm reading from the book. It is sharing that slot with the SSD. What happens if you run the SSD in the M2A slot.

We are not support here it is just a user to user forum. Plus not many of us are here these days.

Plus by looking at all the Bios updates there isn't any for that problem. I would contact support themselves.