When I open the Excel file, an account is demanded every time

I mount nextcloud as a network drive in WebDAV.
When I am going to open the stored Excel file by direct Excel.exe, an account of nextcloud is required by all means every time by nextcloud. And I can’t open the file even if I input an account.
*There is no problem if I download it to my PC. It isn’t data/file protection of the Excel.

Is this a problem of the Excel or Windows or nextcloud?
The PC that an account isn’t required again exists. In other words, it doesn’t occur with all PCs.
All PCs are Windows10. nextcloud is version 10.0.2.

Please tell me the method to allow a file to open without an account being required every time.

Best Regards,