Probably the reason why you got that BIOS message is because you changed processors thus BIOS needed to be reset to adapt to the different CPU installed.
Click on "Accept" and configure your BIOS for the processor you now have installed.
I would check your Motherboard's QVL List for Matisse Processors to see if the RAM you now have installed is compatible with the Ryzen 3100 processor. At least that would eliminate incompatible RAM from the issue.
The RAM you now have is compatible with the 2200g but may not be compatible for the 3`100 processor.
Also do you have your Monitor cables connected to the motherboard or RX5500 GPU card?
By the way if you updated your motherboard BIOS to version F40 did you follow the instructions as indicated: https://www.gigabyte.com/us/Motherboard/B450-AORUS-PRO-WIFI-rev-1x/support#support-dl-bios
If you didn't your RAM is probably incompatible with 3rd Generation processor Ryzen 3100 because you didn't follow the instructions.
If you did, try updating the BIOS and reinstall the 3100 again and see if you still are not able to boot or have no video output. Post any Motherboard Trouble LED lights or Digital codes or BEEPS when powering up.