Gigabyte GA-AX370-Gaming 5 Rev.1

Good Morning,

i hope anybody can help me =)

i have a complete-PC with Gigabyte GA-AX370-Gaming 5 Rev.1 Mainboard and AMD Ryzen 7 1800x CPU
BIOS flashing is dont work because its an OEM-Bios =/

i called the manufacterer and Gigabyte but they cant or want me help to Flash an actually bios .. because its OEM 

i've searched Google and found the AMI V Aptio tool .. but i cant start it .. it Comes an error "46 - error Problem getting Flash Information"
i tried to start afuwin x64 - error
the same error was with afudos

is my board/bios really so hard locked?
or is there anyway to Flash an original bios? 

hope you can help me =)