If the issue persists, the problem might be how your phone communicates with your carrier.
Here is a comprehensive guide to why this happens and how to fix it. i can't download mms text messages
The most frequent cause of download failures is a lack of mobile data. If the issue persists, the problem might be
Finding yourself unable to download MMS text messages is a common frustration, often appearing as a "failed to download attachment" error or a message stuck with a "downloading" spinner. Unlike standard SMS text, Multimedia Messaging Service (MMS) requires a different set of protocols and data connections to handle larger files like photos or group chats. If the issue persists
If your signal bars are low, the phone may struggle to download larger files. Try moving to an area with better reception.