Hello there, @DKC.

Word for Microsoft 365, Word 2021, 2019, 2016, 2013, and 2010, the text will disappear when overtype mode is turned on and the insert key was pressed on the keyboard.

Here's how to resolve this:

1. Go to the File menu, then Options.

2. Click Advanced.

3. Under Editing options, clear both the Use the Insert key to control overtype mode and the Use overtype mode check boxes.

Please know that you can always get back to us if you have other questions. I'm more than happy to help.