Little blue circles

Those are most likely Excel co-authoring indicators. They appear when a workbook is stored in OneDrive or SharePoint and Excel thinks that your Microsoft account has the file open in another window, browser tab or device. They are not part of the worksheet and should not print.

Try this:

1. Hover over one of the circles. If it shows your name or says you are editing, it is a co-authoring indicator.
2. Close every other copy of the workbook, including Excel for the web and any copy open on another device.
3. Close Excel completely, wait a minute, and reopen the workbook.
4. If you do not need collaboration, use File > Save a Copy and save it in a local folder outside OneDrive.

If clicking the circle opens a comment instead, it is the author icon for a modern comment. Open Review > Comments and delete or resolve the comment if it is no longer needed.

If the initials belong to someone else, check Share > Manage Access to see who currently has permission to the workbook.

It sounds like the indicators that another person is also working on that worksheet.  In this case that would be you in another instance.  For example if you opened the sheet in the browser and then opened it in the desktop app.  Or maybe you have a home computer and a work computer.