MSI Afterburner - different fan speed between program window and OSD

I've got an MSI 5700XT Mech OC, and I've got a custom fan curve in Radeon Software. When I open up Afterburner, the Fan Speed slider is showing ~37% in the Afterburner window itself, when at the same time the Fan Speed is showing 51% in the OSD.

GPU is at 32° so according to my fan curve, fan speed should be around 35%

Why are these readings inconsistent?