
Laura W. answered 05/16/19
Microsoft Office Trainer and Author
Apparently, this has been an issue going back at least to Word 2007. Some people have found that having Overtype Mode enabled causes the problem. You can check Options > Advanced > Editing Options.
Also, this was posted by the Microsoft Team on April 24, 2017:
This issue is now fixed in the following builds:
- For Windows Desktop: This issue was fixed in Version 1703 (Build 7967.2139) for subscribers or in build 16.0.7967.2139 for non-subscribers. You may not have been prompted for this latest update as this update is gradually rolling out to our subscribers. To get the update immediately, open any Office 2016 app and choose File > Account > Update Options > Update Now.
- For Windows Mobile: This issue is fixed in version 17.7967.
Hope this helps.