Maintaining the current track changes display setting is very complicated, as the code to do so has changed with every version of Word (i.e., 2007, 2010, 2013, and 2016 all use different methods). In some versions, it doesn't seem to be possible to store and restore the display view. For now, displaying All Changes appears to be the best compromise.
I have some sort of workaround. Just work on the document in a new file without tracking changes, then compare your new document with the old version and save the compared version in a new document. Should work. See here: https://www.pcworld.com/article/147756/article.html
Upgrade Storage
Just a note that I'm also getting this problem. Although I'm using Zotero 5.0 beta (5.0-beta.221+a15261b3b) and Word 2016 (64 bit on Windows 10).
See here:
https://www.pcworld.com/article/147756/article.html