I'm pretty sure the numbers at idle don't matter but at full load, you should be pretty close to 100%. That means the Mobo isn't cheating. Mine is.
I have Asus Prime X470-Pro and Ryzen 1700. Under full load, Hwinfo reported 48-49% deviation.
First I had to remove my overclock before HWinfo even showed the deviation parameter.
Testing right now (with OC), idle vs full load was according to Hwinfo a difference of 100 watts. But my power meter showed a difference of 130 watts.
"Note that this value has a useful meaning only under
full CPU load and values around 100% (95 - 105 %) mean the telemetry is working correctly. "
Source:
https://www.hwinfo.com/forum/threads/hwinfo-v6-27-4185-beta-released.6455/