Page Setup Option Not Available in Excel 365

[ArizonaAnn]

I'm using Office 365 online and am on an HP Chromebook (which I realize is not supported by MS Office).   In Excel, the option for adjusting margins is missing under Page Setup.   I went to File/Options/Change Regional Format Settings as directed here:  https://support.microsoft.com/en-us/office/change-regional-format-settings-in-excel-for-the-web-c206....   However, just as it appears in the example at this link, when English (United States) is selected, the "Change" section is grayed out.   

I need to be able to changes margins in Excel.  Why don't I have the ability to see this option?   I've spent a lot of time with MS Chat, and they were unable to help me.

[#2]

@ArizonaAnn I'm having the same issue.  Has a work around ever been discovered?

[#3]

I'm getting the greyout in some areas also. Not the same pages as you, but similar results. Mine are on the Visual Basic and Macro pages. Maybe there is something wrong with the Excell program.