Rebooting GMKtec NucBox G3 Plus leads to no HDMI signal

[sck]

I have a new GMKtec NucBox G3 Plus (Intel N150 CPU). I've tried several distros (Rocky, Ubuntu, Debian) and all exhibit the same issue. Specifically, if I "shutdown -h now" the system shuts down as expected and when I manually press power, it comes boots properly. However, if I try to reboot with "shutdown -r now" it reboots but the HDMI output has no signal -- I can ssh in just fine in this case -- just no HDMI until I shutdown and manually power back up. I have even tried the latest stable mainline kernel via zabbly.com for Debian 12 to no avail (although it addressed a sound driver issue). The support folks at GMKtec were quick to respond but unable to help with Linux and suggested this forum. I'd like to use this box in a remote location where there's a need to cleanly reboot remotely.