I've never seen that in practice, but that's a great potential cause.
This is almost certain to have its root cause in Windows, not NVDA, as all NVDA does is, essentially, say, "Windows, here's the HTML file for User Guide, take it and fire up whatever you've got set to open it." After the handoff, NVDA is not involved at all.
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
The depths of denial one can be pushed to by outside forces of disapproval can make you not even recognize yourself to yourself.
~ Brian Vogel