Can’t send group text on my iPhone.

Schmidthy wrote:

I just recently stopped being able to send texts to a group chat.

Is anyone trying to add you to the group?

Do more with Messages

• Learn how to leave a group message, or add or remove someone from a group.
• Name your group messages to make them easier to find.
• Use inline replies and mentions to call attention to specific messages and people in your group messages.
• Explore the latest features in Messages to stay connected to the conversations that matter the most.

Schmidthy wrote:

I have tried both with WiFi on and off, I have LTE signal here. I recently updated to iOS 15.4.1 but am unsure if the events are correlated.

I don't think this is correlated with the problem that you are facing.