Group messages isn’t working

I need help figuring out why I’m unable to respond to a group chat. Here are some key items/steps to know.

-there are No android users in the chat (as I created a separate chat and none of the contacts had green highlighted number)

-Group chat name has been changed to reconfigure chat

-I have restarted my phone

-I have turned off iMessage and disassociated number and iCloud email.

-Other group chats I’m on are working

-I’ve tested each individuals number to make sure they have an iPhone

I can’t think of any other option to resolve the issue. Please help