Cannot connect to Cox Account using Outlook 2016

This is an intermittent issue where I cannot connect to my cox account using the Outlook 2016 client running on my Windows 10 latptop.

The error message is "Outlook cannot synchronize subscribed folders for xxx@cox.net. Error: Cannot connect to the server.  If you continue to receive this message, contact your server administrator or Internet service provider (ISP)".

This is what I have tried:

 - taken this account out of the auto send-receive action and performed it manually

 - changed my Cox account password on the cox site and reset the Cox Account in my Outlook

 - allowed Outlook to 'Repair' the cox account automatically, plus I also did it manually as defined above

 - full reboot of the laptop

I can get my email on my iPhone so there does not seem to be any issues with my Cox account or email address.

This happens intermittently and usually lasts a few days after which is resolves itself.

This is most annoying plus I would like to understand the root cause.

Any help would be greatly appreciated.