Primary SSD disappears after sleep or shutdown  

Hello

After sleep or shutdown my SSD with the system on it disappears.
Even in the bios i only see the secondary HD.
Only after couple of resets it appears again in the bios and i moving it to be the first boot option.

In device manager i don't have issues.
I restored the bios to defaults.
Link State Power Management Setting is Off
AHCI Controller seems to be checked in bios.
The Sata cables are new and sitting well.

I dont know what else to check\do ?

its working fine on my old pc and working fine in this pc while its on
something happening when the computer is turn of.

Try on another sata port and its the same,
sometimes after sleep i dont have a screen and then after reset is loses the ssd.

Could it be system problem ? bad windows installation ?

So what should i try next ?
I already restored the bios to default setting.

NewPC: Intel i5 8400
MB:Gigabyte z370 hd3
SSD Transcend 128GB Drive with windows 10 system on - installed on Sata0 port
HD WD 500 GB - installed on Sata1 port

When coming back from sleep or shutdown the SSD drive dissapears so cant load the system
Only after couple of resets the drive is back to the boot and the system is loading normaly.

I connected the drive as secondary in windows 7 machine and it is working fine. don't disappear after sleep,restart.

I connected again in my system as a secondary drive and didn't boot from (boot from other HD) and he is disappearing in the windows and in the bios.

Tries again to install all the drivers, load defaults of bios and nothing helps.

Can someone tell if is the problem with the SSD or my motherboard ?