Unable to Connect to OneDrive and other Microsoft Services

I am unable to connect to OneDrive for Business at home on my Xfinity network and other Microsoft services such as Teams.  I have researched and tried numerous solutions (changing DNS servers, rebooting modem/router, etc., etc.), but it appears from doing a quick Google search that this is not an isolated problem as others have had, and are having, similar issues.  I have my Xfinity modem in pass-thru mode as I use a 3rd party wireless router, but even when the modem is in router mode the issue still occurs.  The problem can be demonstrated by trying to sign into the OneDrive application on my PC or by trying to access the OneDrive website (onedrive.live.com), both of which will time out with no connection.  Trace Route to the one drive site will also fail at the edge of the Xfinity network.  I have also replicated the issue on multiple PCs on my network, using both Wi-Fi and Ethernet connections.

This appears to be an issue that Xfinity has to resolve but I have little luck with getting support to help me with this.  Ideas on what to do next??

Thanks.