PM me with a copy of the Terminal.app output and I'll tell you what to do different.
In the ioreg, I see a device
pci1344,51b1
. A IONVMeController driver is loaded for it. It shows there's one IONVMeBlockStorageDevice which is a Micron_9300_MTFDHAL15T3TDP with some partitions. The same info is shown in the PCI tab of System Information.app
https://admin.pci-ids.ucw.cz/read/PC/1344/51b1
There's another device
pci1344,5196
https://admin.pci-ids.ucw.cz/read/PC/1344/5196
That's the 9400 but no driver is getting loaded for it. The PCI tab of System Information.app also shows this.
Need to see the class code and other PCI info to see if there's a reason the NVMe driver won't load for it.
I think the generic NVMe driver only requires class code 01:08:02.
https://admin.pci-ids.ucw.cz/read/PD/01/08/02
ioreg -filw0 > ioreg_all.txt
will output more info about the devices and drivers such as the product IDs for the parent PCIe bridges.
ioreg -filrw0 -c IOPCIBridge > ioreg_pci.txt
is the same except it will include only everything connected to PCI.
Not sure what to do about that. You can try booting in verbose mode to see if there's a clue there. Is it trying to do TRIM to NVMe devices? Check the logs?
What if you switch the position of the 9400 and the 9300?
What version of macOS? I think you said Ventura? Did you try other versions? Ventura doesn't add anything new to the IONVMeFamily plist except IOPCIUseDeviceMapper whatever that is.
Maybe the problem is the capacity?[/code]