The sudo dmseg command shows the warning Possible missing firmware /lib/firmware/ast_dp501_fw.bin for module ast. This relates to the ASpeed BMS VGA graphics microcode. The simple solution seems to be be to install the non-free microcode blob using sudo apt install firmware-ast.

It would seem that this warning can be ignored, however the warning will remain. The hardware or software? is reportedly end of life 2018, interesting as it is quite clear the related hardware was being sold much later than this.

• Package: firmware-ast (20140808-8) [non-free-firmware]
• Ubuntu 15.10 Server; W: Possible missing firmware /lib/firmware/ast_dp501_fw.bin for module ast

• Linux Upgrade (Debian) - Possible missing firmware problem [duplicate]
• Package: firmware-realtek (20240709-2) [non-free-firmware]

Repository index of firmware blobs for use with the Linux kernel