It's a NUC8i5.
It fails to POST, or let me into settings, unless I remove the M.2 NVMe SSD. The SSD is a WD Black 500GB.
I plugged the SSD into a Linux machine. Kernel sees that it's a WD 500G drive with 4K sector size, but says that it won't actually read data.
I'm replacing it with a Samsung 970 EVO 2TB, but will have to reinstall OS and software.