Sending Group MMS messages failing for others on iPhone?

Checking to see if this is an isolated issue, or it’s just my wife and I somehow.

All of my group messages with a mix of iPhones and Androids are experiencing the same issue. As I understand it, this mix means that the messages are sent over MMS?

We’ll text a message and find it failed—we have to resend everything over SMS. It’s a headache, and I’m unsure if this is making for a bad experience for my Android recipients.

Is there something I can do to fix this?