I had to perform a BIOS update on my Gigabyte 2080 gaming overclock to stop that happening although I still use a custom fan curve. You'll probably find if you set a fan curve in Afterburner with minimum fan speed above about 33%, the fans will run continuous at idle with less noise. Anything less than 33% fan speed can result in that stop/start issue.
I have the twp of the three fans spinning like crazy with the third fan sat idle again. This was the original problem.