Microsoft 365 network connectivity test tool comes to Microsoft Support and Recovery Assistant

Hi PaulAndrew,
I'm using https://connectivity.office.com/ to figure out some issues I'm having with users Teams experience.  The files tab sometime doesn't show any content, but on refresh will sometimes come back.  In some cases the users are not getting to view the files tab at all.

I am running the network connectivity tool & finding that some of the affected users are exhibiting errors in the tool > Details > connectivity > TCP Connection, with the warning failure result showing:

Unblock URL: 

teams.microsoft.com

Test FQDN(s) used were:

teams.microsoft.com

Unblock URL: 

*.office.net

Test FQDN(s) used were:

insertmedia.bing.office.net

Unblock URL: 

*.teams.microsoft.com

Test FQDN(s) used were:

statics.teams.microsoft.com

Then further errors in the SharePoint Online section:

Download speed: Test failed. Unable to test SharePoint Front Door

Buffer bloat: Test failed. Unable to test SharePoint Front Door

I have around 10 users affected in our estate & they didn't experience this issue 4 months ago.

We haven't made any changes to port blocking etc & in all cases the users are only having the issues when working remotely.

Any ideas would be appreciated.

Cheers,

M