So it seems, that randomly, every couple of days, my sensor panel will read NaN °C from the "T_Sensor" under temperatures.
Restarting AIDA 64 Extreme does not solve it. Rebooting the PC doesn't fix it, even powering off the PC and restarting does not solve it issue. I have even reinstalled AIDA 64, and still got the same result.
Powering down my PC and turning off the power supply, waiting a few seconds, then powering back up does solve the issue for a day or two.
As mentioned above, this is with my Asus ROG X570 Crosshair VIII Hero motherboard, I am using the latest version of AIDA 64 Extreme (registered) and Windows 10.