Strange NVMe “BootDevice Not Found” error on HP EliteDesk 800 G2 Mini

I installed Debian 11 on Samsung SSD 970 EVO Plus 1TB… everything worked as expected. I disconnected (removed) NVMe from computer and booted to Tails using USB flash drive… everything worked as expected. I disconnected (removed) Tails USB flash drive and connected (added) NVMe to computer and booted… “BootDevice Not Found” error was thrown.

BootDevice Not Found

Please install an operating system on your hard disk.

Hard Disk - (3F0)

F2 System Diagnostics

For more information, please visit www.hp.com/go/techcenter/startup

Running “Hard Drive Check“ / “Quick Test” in “System Diagnostics” reports following.

SMART Check : PASSED
Short DST : NOT AVAILABLE (1: NOT AVAILABLE)

Strangely, I can boot to Debian (using same NVMe) on another computer (in other words, disk is not defective). What am I missing? Thanks for helping out!