iOS 26 iMessage Group Chat Duplication Issues

Although this might not apply to everyone, I will share my experience.

I started getting this after updating to iOS 26. The issue propagated to my Macbook before updating to the latest macOS, so somehow it was the iPhone that was propagating the issue across iCloud.

After multiple seaches online etc, I realized something:.

The duplicate group did not have my contact in it as part of the members. The old group did.

Since I mainly use my phone number as the main contact for messages, I added my phone number again to the "new group".

This made the groups "merge" into one again.

I then realized that the "fix" didn't replicate to my Macbook. I did the same actions again on the MacBook, and it worked.

This took some fiddling.

Important: When searching for your contact name, make sure to drill down into the details and select only the phone number or email that you want to add to the group. Otherwise for me, it added me twice, and of course, the group was again duplicated and split into two.

I hope this is able to help someone, as previously I had tried everything else and nothing worked.

TL;DR: Try to find if there is a mismatch of contacts (in my case it was me) and make sure to add the missing person (or remove the extra one) from the duplicate group.

I've literally just done this, so I don't know if this is a permanent fix, or if this will happen again. After all, this doesn't actually fix the bug that caused it in the first place so it might happen again.

I can share a positive end: the separate text strings have now recombined for me. I tried a mix of things (restart; turn imessages off under settings then restart and turn iMessages on; turn on/off RCM; check contacts to make sure that contact who seemed to cause the initial split had her email and cell number on the same contact card, etc) and ultimately I think it may have resolved on its own. A friend has had this issue and she said it resolved on its own after a few days. GOOD LUCK!

Phone updated to 26.1 while I was sleeping, the same day I posted the above. Here I am the next day and all of my chats are back to normal.

Adding another voice to this topic. All four family members are having this happen. Multiple group chats have been split, with each person seeing a different message history after the split.

For one of those group chats, Chat A contains messages from around three years ago up to the present. Chat B contains messages older than three years. I renamed Chat B to something like "Chat B (old)" and half of my family complained that was the chat that contained all of the newer messages on their phone; the opposite of the split on my phone. This started a slew of awkward chats bouncing between Chat A and Chat B.

For about a month, only one group chat was affected. Jump ahead to this week, and a different group chat has just been split. This time, Chat C contains messages from 2021-present, and Chat D contains a multi-year chunk from the middle of that same time period.

Additionally, my daughter mentioned that yet another group chat split on her phone a couple weeks ago. But it still behaves normally on my phone (single thread, not split).

Chat A/B split occurred on 8 Nov 25.

Chat C/D split occurred on 8 Dec 25.

It happened with two group chats for me. The only change was me updating to iOS 26.

I went through the suggested steps of turning different things off in the messaging app, restarting the phone, turning the app things on again. Still not fixed.

Just voicing my agreement with OP here, this JUST started happening to me and apple support has basically said "did you try turning it off and on again" which does nothing. It's literally only one group chat that has done this so far, and its not doing it for any one else in the group chat. Everyone is on imessage too. I don't want to have to delete everything and start over because that is an inconvenience for everyone else in the chat.

I’m also having this issue!

In this instance, my friend got the new iPhone 17 and messaged in our group chat, someone responded and it popped up a new chat so now it is duplicated and all other users see the new chat as the original one and I see the new chat as the old one?

it’s so confusing. I updated to iOS26 yesterday, based in the UK and have an iPhone 16 Pro.

i also tried the on/off and that didn’t work.

This has been happening with my family’s group iMessage chat for like a year now. It’s been pretty frustrating to deal with with 6 people texting and the messages being all over the place. This started before the ios26 update for us.

Were you able to find a fix? Same issue here. Tried to turn on/off and also tried turning off RCS and restarting. Nothing has worked. Thanks for any help you can provide.

I’m having the same issue as everyone here - has anyone else heard from Apple support?

I’m having the same issue with multiple group chats. No change in different devices being used, just a duplicated group text. Same people, same devices. If there was a way to merge them, I would! Very frustrating. Only started after iOS26 update. iPhone 16 pro here.