My CPU fan/case fans are suddenly no longer ramping up

Edit: Gigabyte GA-Z270-HD3 mobo

Seemingly, my fans (CPU, and case fans) are no longer ramping up as it gets hotter. I just did a couple of stress tests in Aida64 and OCCT, and both times CPU got to about 75-80 very quickly and the CPU fan stayed at it's base around 500rpm (as monitored by Aida64 and HWinfo)

I have fairly aggressive fan profiles setup in my Gigabyte Bios (Smart Fan 5 in the bios) and it should be ramping up pretty quick. It certainly did until now/whenever this started. Checking the fans in bios, they respond to manual adjustments from within the bios, but don't actually spin up based on temperature when in windows. They're all PWM fans on PWM headers and like I said they were working fine until I noticed this.

I've been doing some heavy gaming and my computer has been rock solid during it, so I don't think it's overheating. But the stability tests will stop once it reaches 90degrees or so.....and the fan isn't ramping up seemingly. It seems to stay between 500RPM and 800RPM as measured by HWinfo. But it should be higher (Noctua U14S CPU fan has a max RPM of 1500)

I've checked my bios - fan profiles are still there so it should be working. The fans are spinning, yes.

Any ideas??

EDIT: This is what Smart Fan looks like ....shouldn't there be fans here? O_o