Question new build freezes randomly

[flasher33]

HI all.
I just finished building my new Rig and I am facing an issue where every now and then the PC freezes for a sec or two then works fine.
I hear the fans ramp up when the freeze happens.
here are my specs:
CPU: R9 3900X
MB:Gigabyte X570 Elite WiFi
RAM: G.Skill Trident.Z 32Gb @3200Mhz (XMP) enabled.
Storage: Samsung 970 500GB M.2
VGA: RTX2060
Cooler: NZXT X72
PSU: Gigabyte Aorus 750 80+ Gold

checking HWinfo I temps in idle are between 48 to 59 C

need your advise and thank you.

 

[flasher33]

Mannaged to find the cause.
It was from the m.2 drive. I simply changed it to an ADATA one and it worked fine.
As this is my 1st time to install an AMD cpu 3900x I noticed the frequency of the cpu varies from 4.0 to 4.3 and so on and although I have an Nzxt x72 cooler Temps vary between 40 to 50's on idle. Is that normal?