my system is 1 year old and it works fine but i'd like to know if is normal that all my fans stop after POST. After power on, if I get into the BIOS all the fans run as they should, but after POST before loading OS, all the fans stop working for about 1 seconds and then restart and never stop again (until next boot of course).
I would like to know if it's a normal behaviour or something to be worried.
To be honest, it has always been so, since first boot 1 year ago. My system runs fine, but looking around the web i can't find similar cases about.

Here's what happens
vlc-record-2019-07-19-19h11m41s-20190719_184100.mp4-.mp4 - Google Drive

My SPECS are:
-H370 Aorus Gaming 3 wifi (BIOS F11)
-Intel core i5 8600k
-Cooler Noctua NH-U12S (dual NF-F12 fans)
-GPU GTX 1050 Ti Zotac ZT-P10510A-10L (drivers updated)
-SSD Crucial MX500 250 GB
-HD Western Digital Blue 2TB
-HD Western Digital Red 3TB
-PSU Seasonic focus+ gold 650
-case: cooler master N300
-fans: NF-A14 front intake, 2xNF-S12A back and top exhaust
-Win 10 pro 1809

Thank you very much