I got a reply from Gigabyte Support regarding the raw commands to configure the bmc/ipmi from ubuntu etc:
sudo ipmitool raw 0x32 0x66
I think these commands should also work as the above command is from the OpenBMC standard:
https://download.lenovo.com/servers_pdf/bmc_command_list_specification_v0.1.1.pdf
I tried the above command and it worked once, it got the web interface running again with same IP and login details (what exactly did it reset?!) so I changed it back to dedicated and now it’s broken again. What’s weird is that currently the MLAN and other port lights are dead until you have at least two port plugged in. And this includes add in LAN cards and even USB NIC adapters. The BMC takes over any LAN capable device! How this is even possible I have no idea. So right now, I think my only choice is to RMA the board again. But I will push for a refund, I’m done with this board.