Consumer Cellular APN MMS settings not working after WP 8.1 Update

My folks' two Lumia 520s on Consumer Cellular (an AT&T MNVO) took the 8.1 upgrade without issue a couple weeks back, however they now can't receive MMS messages (a photo attached to a text message for example) anymore, the settings we used successfully previously were:

Navigate to: Settings / cellular + SIM (add Internet APN and MMS APN if not present)

Edit Internet APN:  

APN= att.mvno

Edit MMS APN:

APN= att.mvno

WAP gateway= proxy.mvno.ccmobileweb.com

WAP port= 80

MMSC= http://mmsc.cingular.com

MMSC port= 80

Maximum MMS size= 10485

Has anyone successfully gotten this to work post WP 8.1 upgrade?  Currently it indicates that there is media attached to the message but will not download it when clicked.  Thanks -

Had a similar problem as was noted in this thread:  Using a BLU WIN HD 510u pone. Consumer cellular finally got back to me after an email I sent.  Someone was gracious enough to evaluate the issue and got every thing in sync.  Settings as follows:  based on LTE windows phones ( They updated the account to LTE network)

APN: ccdata

User Name: blank

Password: blank

Proxy Server: Leave blank

Proxy Port: Leave Blank

MMS APN settings:

APN: ccdata

WAP Gateway URL: proxy.mobile.att.net

WAP Gateway Port: 80

MMSC URL: http://mmsc.mobile.att.net

MMSC Port: 80

Save this APN information and make sure it is the active APN in the phone; turn on data roaming, turn off WiFi; Power off the phone and bring back up (make sure it is connecting to the right configuration) open up a browser to connect to any webpage or do a quick search to see if the phone is connecting properly. Don't forget to turn WiFi back on!

These settings worked like a charm on My Blu Win HD 510u Phones.  Note: I also left the network settings on automatic, and the IP address on IPV4V6  maximum size is also left blank.  Consumer Cellular 800.686.4460

Yes, made sure the picture was also less than 1 meg in the event size was an issue. I have also completely reset the phone back to original factory specs and then retried and verified Wi-Fi was off as well.  No luck.

Did you try sending a pic from a phone to itself?

I have a similar problem as well, except we are  using Consumer Cellular and a Win HD 501u Phone by Blu and sold by Microsoft with windows 8,1.

I used the exact settings as above (since consumer cellular uses ATT network) and have virtually no luck in being able to send a picture attached to a message.  I have three (3) of these phones just recently purchased and have had success with one phone working for both send and receive over a 4 hour period and then suddenly unable to send or receive any pictures associated with messaging since.  I have made sure WIFI was turned off during all these processes.  Consumer Cellular keeps saying it's a windows problem.  So far I have spent over 30 hours attempting to get this working using various settings.  It would be great if someone with access to the programs would at least compare these issues and correct the protocol to fix it, whether it be the cell phone carriers or Microsoft configuration issues.  I just don't now where to access these departments that may have a little intelligence to track out these issues. 

Yes Frustrated.!