A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Hi Justin,
You may inactivate Excel add-ins and check if you can use over type mode normally.
Here is the steps to inactivate Excel add-ins:
- Go to File>Options>Add-Ins.
- Choose Excel Add-ins in the Manage box and click Go.
- Clear the check box next to the add-in then click OK.
Note: Inactivating add-ins does not remove the add-ins from your computer. You can add them back.
If above don't help, we suggest you uninstall Office and reinstall Office from portal, then check the result.
Here is an article for your reference:
Regards,
Tina