Greetings Jezzebelle85,
Thanks for posting in Apple Support Communities.
You've completed some great troubleshooting steps so far. To help you solve the issue you're having with sending a group message to Android devices, we suggest following these steps:
• Go to Go to Settings > Messages > Messaging > Group Messaging and be sure that feature is enabled as well.
If it is enabled, toggle it off and back on again.
• Restart your iPhone. This may seem like a simple step to take but can often resolve several issues:
"1. Press and hold either volume button and the side button until the power-off slider appears.
2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
3. To turn your device back on, press and hold the side button (on the right side of your iPhone) until you see the Apple logo."
• Verify if you have a carrier update available. If so, you can complete it as shown here: Manually update your carrier settings on your iPhone or iPad
• Be sure you're running the latest software version. This is to ensure your iPhone runs smoothly. (Secure your data with a backup before proceeding): Update your iPhone or iPad
We hope this helps.
Have a wonderful day!