jeg kan ikke fjerne deling af en excel fil og ukendte logger sig på

Hello, thank you for reaching out to Microsoft Q&A.

1. Have you already tried removing the shared links or permissions from the Excel file’s sharing settings?
2. Do you see these unknown users accessing the file through the OneDrive/SharePoint sharing settings?

If you are the file owner, select the file or folder you want to stop sharing > select the Information tab in the upper right corner to open the details pane > and select Stop sharing.

For reference, see -

Stop deling af OneDrive- eller SharePoint-filer eller -mapper, eller skift tilladelser

Let me know if you still need more help.