Some reference to use Cmd+Tab, shows an Application Switcher opens
suggests that could be used, in some macOS and applications to switch.
"Or you can click and hold on the Word icon in the Dock. Do so and at the
top of the contextual menu that appears you'll see a list of all the open
documents. Choose the one you like and it becomes the active document."
~ https://www.macworld.com/article/1135977/switchwindowshortcuts.html
[An alternative may be to explore to see what you find by using
'Keyboard Viewer' to expose those keys, in open/viewer in Finder.]
Others suggest Control+Tab, to switch between open tabs.
I've found 'microsoft help' forums good for Mac questions.
• How do I switch between open applications using my keyboard? | etc.usf.edu/techease
https://etc.usf.edu/techease/mac/files-sharing/how-do-i-switch-between-open-applications-using-my-keyboard/
Maybe it's not useful only in within ms office or word.
Or for other versions macOS?
An external wired keyboard is helpful, for troubleshooting hardware, too.
Sorry to only guess in this matter & not be helpful.
Take care & good luck!🌤🐢🌻🌿