Outlook Problems with comcast.net email address

All of a sudden I can't get email using Outlook.  I can use Webmail, and it's working on my phone.  This is O365, everything is fully patched and non-comcast.net emails work.  I've tried using my desktop at home, and a laptop elsewhere; same problem on both machines.  Deleted Outlook Profile and tried to re-add a new profile, using the correct imap.comcast.net manual settings.  When I use SSL/TLS it immediately returns a credentials error; when I use STARTTLS it hangs for a while before erroring out.  In the beginning I was receiving an error "The name cannot be matched to a name in the address list" trying to setup the account in Outlook but I'm not getting that anymore.  I've tried checking/unchecking the "Allow unsecure applications" option (currently checked to allow) and disabling 2-factor authentication (currently off but I'd like to re-enable as soon as I get past this). 

This has to be related to the specific account/email address but I can't figure out how to fix it .... assistance appreciated.