Cannot send or receive Comcast email from Mexico using Outlook for Windows or Android

I am unable to send or receive emails from Mexico using Outlook for Windows, on two Windows devices. I keep getting prompted to enter my Xfinity password during “send-receive”, but the password is not accepted. 

• Other email providers work fine on the same Outlook installations. There’s another IMAP, an Exchange accounts, and two POP3s… none have a problem on either device. 
• With Android on Wi-Fi, I keep getting prompted to “sign into comcast.net”, but it doesn’t work when I do. With Android on mobile data, using my Mexican cell provider, it doesn’t work.
• But with Android connected to T-Mobile (roaming), I can retrieve emails without a problem.
• When accessing Xfinity email via the website interface, there’s no problem.

• When using our phones and laptops just over the border in San Diego, there’s no problem.
• When using a VPN, Outlook for Windows works…but Outlook for Android does not work on wi-fi, even with a VPN.
• The IP address assigned by my ISP is not blacklisted, as far as I can tell.

 Since my PW is correct, and no other email accounts are affected and everything works fine in the US, it leads me to believe that Comcast is blocking Mexico IP addresses.

Is this true?

Can I get myself un-blocked?

My email address was compromised during the Comcast hack a while back… could that have something to do with it?