Please install the monitor driver LG Product Support | LG U.S.A
Please update the Motherboard BIOS
Looks like the EDID needs to be update it https://en.wikipedia.org/wiki/Extended_Display_Identification_Data
BIOS is up to Date, Version: 1.2
Mainboard: Asrock Fatal1ty Z170 Gaming-ITX/ac
Latest Displaydriver is installed.
How can the EDID be updated? Only by the Motherboard Manufacturer?
When you plug a Monitor/TV to the system, the graphics driver controler reads the EDID, that is why you need to update the graphics driver and install the monitor driver.