MMS quit working

Carrier: Phreeli (MVNO on T-Mobile)
SIM type: eSIM

The problem: MMS stopped working at some point — either after an iodéOS update or after changing some settings. Data and SMS both work fine, but when I try to send a picture message it just hangs on “Sending” and never goes through.

What I have already tried:

  • Confirmed mobile data is ON
  • Manually entered T-Mobile APN settings (fast.t-mobile.com) with correct MMSC
  • Tried alternative APN (epc.tmobile.com)
  • Tried IPv4, IPv6, and IPv4/IPv6 protocols
  • Reset mobile network settings
  • Checked iodé blocker — Messages app does not appear in per-app blocking list
  • Tried QKSMS, Silence, and Quik as alternative messaging apps — none worked

MMS worked fine before on this same eSIM and carrier. Network shows as T-Mobile.

Any help would be greatly appreciated. Thank you!