Hi PatB_365,
To determine whether background programs are interfering, please start up your Mac in safe mode, then open Word and check if there are some differences. (To start up Mac in safe mode, you can refer to
Use safe mode to isolate issues with your Mac.)
Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites or any support related to technology.
Also, we suggest you check if your Excel is the latest version. Please open Excel > click Help on the top menu > choose check for updates, then update your Excel to the latest version.
If the issue disappears, please refer to View multiple panes, sheets, or workbooks to use this function.
If the issue persists, please provide us with the information below:
- Open Excel > click Excel on the top menu > About Excel, capture a screenshot about your Excel version and share with us.
- Click Apple icon on the top menu > About this Mac, share your MacOS version with us.
- What changes have you done before the issue appeared?
- Please share a screenshot about*"but I am unable to arrange them to view them side by side, because the arrange option is greyed out.* ”
Regards,
Rosen