I picked up a 2015 Retina MacBook Pro 13 and upgraded the internal SSD to a 500GB Western Digital Blue SN550 drive. The machine was running like dream, actually impressive for a little i5! But, it has recently started kernel panicking when left on sleep for any reasonable length of time.
I'm no expert when it comes to the panic diagnostic info, but I don't suppose anyone can advise and point me in the right direction?
The Kernel Panic is referencing an SSD issue as mentioned here in the Kernel Panic log you posted:
nvme: "Fatal error occurred.
There is a possibility the issue could be related to the SSD Adapter you are using with the M.2 SSD. The only adapter I've seen recommended on these forums is from Sintech. Users with other brands of adapters seem to have compatibility issues.
You can try unchecking "Put hard drive to sleep when possible" in the Energy Saver System Preferences in case the SSD has trouble waking from sleep.
Kernel panic when MacBook sleeps
