Sapphire Radeon RX 550 4Gb no work

I have a problem with my "Sapphire Radeon RX 550 4Gb" card
OsX BigSur detects it as a "7 MB Monitor".
I found this EFI (attached) for my motherboard, but it was made to work with an RX580.

I know it can only work if it has POLARIS chip so I checked Device ID and it gives me 0x699f .

As a boot I use OC.

Thanks for the help .

Author: ifreddy