Issue with MMS group messaging. sending to a group with an Android user results in individual texts.

I have an iPhone SE (2nd Generation) with T-Mobile.

Just updated to iOS 17.

Here's the issue I have:

When sending a group MMS (i.e. to a group with at least one Android user), the messages I send are received as individual SMS's, instead of to the group. And similarly, when someone else sends a MMS to the group, I receive it as an individual SMS.

This issue only started occurring in the last week or so, once I installed an eSIM (traveling abroad). While I was abroad, I turned off group MMS to prevent unwanted charges. After I returned to the States, I deleted the eSIM and reactivated group MMS and SMS, but now group MMS doesn't work.

I have group MMS turned on, SMS turned on, and have toggled both on and off multiple times. I've also tried the solution described here (Just got iPhone 14 — can’t text android p… - Apple Community), to no avail.

Any help?