iMessage "You left the conversation."

I'm seeing these phantom "you have left the conversation messages" too. I wasn't in a conversation and haven't left one, especially not at 3:30am.

wvincal wrote:

I have an iPhone 8 running iOS 11.4. For several weeks now, in most if not all of my group text conversations in which there are both iPhone and Android users, I keep getting a notification that says:
iMessage

You left the conversation

<stamped with date and time>

I am not manually doing anything to leave these conversations, and it appears that leaving the conversation happens at a time when I am not even using my phone. Can anyone explain to me why this is happening and how to stop it? I don't seem to be missing any of the texts in these group threads; it's just annoying. s!

Thanks!

Sorry you can't leave a group MMS - iPhone and non iPhone user, you can only leave a group imessage - all iPhone users.