Hmmm ... now that's odd, for sure. I installed Aquamarine on an SSD in my Travelmate laptop and laboriously confiugred it completely as was the Solus Budgie SSD before it. But the first time I shut it down, it wouldn't boot again.
Puzzling indeed, but I assumed I'd unknowingly done something wrong, and I reinstalled Aquamarine again, and configured, etc. Laboriously, as I wrote, because this little laptop is running on a Celeron processor.
But when I shut it down again (politely), it wouldn't boot. The UEFI doesn't recognize it as a bootable disk. So I replaced the Aquamarine SSD with the Solus Budgie SSD I'd removed earlier, and that booted just fine.
I may try to figure this out at another time, but for now it's more drama than I want to deal with. I'm almost scared to shut down the VM on my main laptop, but I guess I've gotta do that eventually. I'll let y'all know if that does the same thing.