I've had a problem a few times recently when powering on my PC that it would boot to the BIOS screen instead of loading windows.  I have W10 installed on a 256gb M2 drive and when it boots to BIOS it says the M2/SSD is not present, but my other TWO physical drives are listed.  After a few cycles of powering down and restarting, I'm able to get Windows to boot up and everything runs fine.  My initial thought was the M2 drive was failing, but wouldn't it fail outright instead of working occasionally?  I've also noticed recently a soft, MUFFLED clicking sound coming from my case which I've traced to the PSU, so I'm wondering if that's the problem as WELL (even though its new, only about 6 months old).  I did update the BIOS through MSi so that's current, but short of just leaving the PC on all the time and NEVER powering down, I'm not sure what else to do.  Any suggestions? 

Specs: 

MSi B450 Tomahawk mobo
Ryzen 5 2600 CPU
Nvidia Geforce 2700 Super
32gb Corsair Vengeance RAM
Intel 256 M2 ssd running Windows
1tb internal HD
2tb internal SSHD

Thanks! What PSU ? ?It's an EVGA Supernova 750 G5 80 Plus goldA friend of mine mentioned it might be the mobo causing the problem...?  I built the PC since everything these days is pretty much plug and play, but issues like this are beyond me, other than just throwing money and new parts at it.
Just following up hoping for some suggestions...
Sorry for your wait for a reply

I have checked the compatibility of all the components in your system, There doesn't seem any problems there, You don't give the model of Intel M2 drive as there is only 4 on the MSI website tested with your board maybe the non boot is a problem with the board and M2 drive.

The ticking sound from the power supply. Is this only with the computer powered up or even with it plugged in before the computer is powered on?

Either way the power supply shouldn't tick. And you could have it replaced under warranty.
Normally when a power supply ticks is a sign it is overloaded or not up to handling the load. There is 2 power supplies in one, a 5 V standby supply and the main supply. The 5 Volt standby powers the startup circuit and some usb ports, it would pay to check the USB ports for damage.

Keep US posted what you find
i had a similar problem and found out my video card was overheating my m.2 ssd , also check the mem banks on ram , they can interfere with the channel of the m2