When trying to setup the Video Alert Format for our phones, there are no attachments with the MMS messages when using the Send Test Clip option. The devices are LG Nexus 5s running Android Kit Kat 4.4.4. MMS messages are being received by the default Google Hangouts app. MMS videos sent directly between the phones function properly.
This does work on the T-Mobile phone when selecting “Phone (AT&T/T-Mobile/Blackberry)”, but not when selecting “Android”. On the AT&T phone, no option seems to work, in either Hangouts or Textra SMS.