S6 M10 fan problem

Recently we've got a problem with one of our S6 consoles. After the latest update, the M10 master module's fan keeps on spinning on high rpm.

I know that when I boot up the S6 first starts with high rpm fan, but after a few seconds it usually switches back to normal low rpm fan operation.

Otherwise all functions work properly, but with this fan problem, it is very loud.

Any ideas can help.