I have MS Word for the Mac, Version 16.113.3 (26092714), running macOS Tahoe 26.6.2 on an all-in-one iMac desktop . Apparently there is a "feature" that causes MS Word for the Mac to spontaneously expand its window from a partial screen to the full screen. I have seen this happen at a time when I am not touching the mouse or the keyboard.
From what I have learned on line is that this is caused by MS Word for the Mac monitoring it's window size compared to space available on the screen, and when it senses that space is available it spontaneously expands to fill the space. If the original window is displaying a single page it switches to multiple pages per window. This is unbelievable behavior, really, and VERY annoying!!!
How can I keep this from happening?