@techknowbabble said in GRUB waits for confirmation:
What did finally work was re-installing with the 'no serial' option and everything seems to be working as expected now. I only have a handful of XCP-NG installations under my belt but I wonder if this is a known bug or if anyone else has had a similar experience.
It's not something I've ever seen before and I've done quite a few installations but I can think of some possibilities as to why something like that might fix the problem. My best guess is that there's something built into, connected to, or otherwise in your system that looks like a serial port (maybe even a real serial port) that spits out a character or two into the system at boot time, confusing GRUB and stopping the normal boot process. The bad KVM I mentioned before was doing something like that, throwing a bogus keypress into the system at boot time.