A family of Microsoft word processing software products for creating web, email, and print documents.
We are not printer experts. Try asking this question on the Cannon Support site. Give them the screen capture.
I found a review for a 922 dated 2013, so your printer is probably at least that old.
At first glance I thought it a font issue, on further review I agree with Doug it is most likely a printer head issue. One thing I noticed was that the problem seemed to be limited to a specific font size. The larger and smaller fonts seemed OK. That suggests to me that there may be an issue with the mechanism that pulls the print head across the paper. At that specific font size it may be slipping.
As to why the problem is limited to Word, my guess would be the way that the Word program interacts with the Printer Driver is slightly different. For example, my HP printer can actually use drivers for 2 different printer languages, and 2 versions of one of the languages. Each one commands the printer slightly differently.