Good catch. The Gigabyte board looks like it uses 2 mOhm resistors instead of the 5 mOhm like the others.
The FE uses this measurement IC
It can be programmed by the firmware to trigger alerts based on the voltage drop sensed on the shunt. So therefore the the board firmware has to match the actual board or the power measurements will go off the rails.
It makes sense that the Gigabyte firmware doesn't work on FE. The GPU thinks there's a power fault since power draw is 40% of the expected.