I just had to reset the SMC to get my PCIE drives back, after resetting the NVRAM didn't work; all seemingly from just unintentionally plugging my USB drives back into different ports. My theory is that whatever is stored in the SMC (and NVRAM?) is vulnerable to being "invalidated" by what ought to be innocuously minor configuration changes between one boot and the next.
I'm tempted to upgrade to the Highpoint Rocket 1104 (the passive version) - so it'd be very useful to hear what experience anyone has had already with that specific card on the Mac Pro 2019, and with which SSDs.
Yeah, its weird. Seems to be different results for different users with the same mac, NVME card and system version (but then it always seems to have been like this for Apple, eg, I intall a lab of say 20 iMac & cloned systems & three might be realy weird, no reason).
My personal experience with this to date:
7,1 mac pro, Sonoma 14.4.1, Sonnet 4xm2 PCIe with Samsung 970 EVO+.
This mounting issue happened all the time with earlier versions of Sonoma; 'seemed to stop' or at least got a little bettter at 14.3.
The one thing that set this 'no mounting' off again - & including now on 14.4.1 - was installing some new sw & something with drivers, eg, UAD plugins, Softraid etc. Because of the drivers & re-boot I can only assume this could be something to do with mac os security bs [?] Otherwise, 14.4.1 now always mounts correctly.
The only thing that would bring mounting back correctly was indeed an NMC reset immediatey followed by zap PRAM. Still the very odd thing about that is that this computer is in effect ALWAYS with an SMC reser becuase this studio is powered down at a main UPS unit when not in use.
PS
don't get me started on the dreadful mess that is date-stamping on mac os. Unbelievable.