I have a Note 3 and since the 4.4.4 update, or somewhere around that time, my phone has been near unable to receive MMS. Most times the MMS just sit in a permanent state of downloading or failed to download. When I'm lucky the messages come in 20 minutes to 3 days late. From what I can tell online my APN settings are just messed up from the last update, but the APN settings are locked and I can't change them to fix it (unlike every other carrier). I have done a factory reset, pulled the battery, and pulled the battery and SIM card for 15 minutes.