Additional file-related features and issues within Microsoft Teams for business
Hi Michelle,
Sorry for the trouble caused and apologies for the delay in the response.
Per the description shared, it seems the users in the Excel file are applying the filters in the Excel sheet and you are having difficultly to remove the applied filters. But as you mentioned, the Clear Filter button in grayed out in the Excel sheet, can I know whether you are referring to the highlighted option in the below screenshot:
If yes, I would like to let you know that to remove the filters in the Excel worksheet, you need to go to the Data tab> And Click the Filter button:
At last, I am afraid that if you protect the Excel workbook with a password, users in the Excel workbook can't work together because protected Excel workbook can't be supported for co-authoring which is AutoSave will be turned off.
Best Regards,
Chitrahaas