I'm guessing it's the same common issue present on many Gigabyte AM4 boards. The IT8792E (and perhaps others) doesn't work with the kernel driver. There are workarounds but they make it so that other ITxxxxE chips don't work. I have a Gigabyte X570 Ultra and can only use ~half of the fan headers with lm_sensors. I haven't been able to get them all working.
I have ASUS B450M PRIME GAMING and after installing the driver, the chassis fan sensors were detected and I could use CoolerCtrl to draw the fan curve.
I don't quite like CoolerCtrl because of its UI, seems to be web based, but it works and has a daemon mode to start minimized on startup.