Question Bad BIOS update (i think)

Sep 16, 2019

I currently own a i5 9400f and a tuf b360 m plus gaming br and i´ve updated bios to the latest version

Everything was fine ( used computer several times) until a restart ,the computer gave me a black screen saying that the vga card is not supported by the uefi firmware and it enabled csm mode ( weird because i was using the computer fine, without csm enabled but after a restart this happened)

I rolled everything back to default (csm disabled) and the computer is working fine

That message was completely random and i don´t know now

Is there something wrong? Note that i can acess bios just fine now ( csm disabled,default settings)

I´m a bit worried now , what happened? Should i ddu the vga or what should i do? I have a galax gtx 1060 oc (factory oc i didn´t made any oc to the system)

Also , what would happen if the BIOS update was bad? I updated the bios through bios via asus flash thorugh the network ( the safest method possible i guess)

I also wanted to know if there is a way to rollback bios to a previous version

Thank you