Yes, that is typically my experience. A reboot will resolve the problem, but not for long. I use Word and Excel a great deal, but it is not a mission-critical app. And when I return to it an need the Help access or the feature that gives you extra forms or even routine forms like page number placements the problem returns.
The annoyance is at a very high level.
I see this behavior in all my Office apps: Outlook, Excel, Word, PowerPoint, and Publisher. I think it has something to do with maintaining a reliable connection to Microsoft's servers. This has been an issue for at least two years, maybe more, and yet to be resolved. I use Outlook on the desktop quite a lot and it loses it Help functionality often. Some days it fails in minutes, other days it runs all day without issue. I am connected to my Microsoft account when the Office apps are failing. All my other internet connected apps on my system like those from Adobe, Google, and Zoom continue to work fine. A lot of people have reported the issue but there must not be enough of us to get Microsoft's attention.