Question 1080ti fan ramping up for no reason.

[gijoe50000]

So I just noticed, for the last day or two, that my gpu fan(s?) seems to be reamping up for no reason.
It's a 1080ti MSI Gaming X.

My GPU temp is usually only about 30c at idle but lately the fan ramps up to, I'm guessing, 50-70%. I don't know exactly, because the speed is not being shown. It's like the fan is ramping up by itself, independent of temps or fan curves.

I think, also, that it's mainly just one fan, the one closer to the front, if that makes any difference. Last night for example, my fans should have been stopped (<60c) but the front one was running quite loud while the rear of the two was stopped.

Another time both were running on manual, like 30% just for testing, and I manually held the back fan with my finger to stop it, and then the front fan took off up to 60-70%.

Anybody know what's going on here? Or come across something similar?

I'm running the latest Windows 10 Insider Preview, so maybe that's something to do with it, maybe not, I would have thought that the GPU would be independent of it, but maybe it's the Microsoft drivers that Windows put out.
The Microsoft\Nvidia driver is 435.27.
I'm running Afterburner and Speedfan, but even with these closed it still ramps up.
I'll probably install an Nvidia driver from the website to see if it makes a difference, but I'[d like to know if anyone has experience with this, or any info on the issue..

 

[gijoe50000]

Anybody?
This is still happening, even after changing drivers, and updating Windows. And it happens whether Afterburner is running or not.
If I switch to manual fan speed on Afterburner, and then raise the fan speed to 70-80% (and apply it) and then bring it back down again, the speed goes back to normal. But then a few minutes later it just creeps back up again.
But Afterburner doesn't reflect the speed. It thinks my fan speed is only about 25%.
Hardware issue?
Bios issue?