Android Messages app chat feature question

[poit57]

At the end of August, I switched from an LG V40 to a Samsung Galaxy S20. I powered off my old phone for about a week before I turned it back on to reset and prepare it for a trade-in. It was only after the old phone powered on that I realized why I hadn't been receiving text replies from my brother and cousin. All of their messages were being delivered to my old phone as chat messages through Android's chat feature.

All other messages were backed up and transferred to the new phone, but I never figured out how to transfer those chat messages that arrived on my old Android phone in that week after I switched to the new phone.

Now a new issue has popped up regarding the chat feature. I helped my brother mentioned above switch to iPhone last night. We used Apple's Move-to-iOS app to copy all his messages to the new phone, but I found out this morning that he isn't receiving my texts on his new iPhone. Is there anything he needs to do from the Android phone other than toggle off the "Enable chat features" option from the Messages app?

 

[SpookDroid]

RCS messages cannot be backed up, unfortunately (at least not by 3rd party apps or transfer apps that aren't 'native' to the app you're using; i.e Samsung's Smart Switch cannot access RCS messages from the Google Messages app and Google's Back Up options cannot access the Samsung Messaging app's RCS chats). If done properly, you shouldn't have to 'turn off' or do anything on the old phone and should be getting RCS messages on the new one as soon as the same number is registered with the Google Messages app. If you changed phone numbers on the SIM card, then yes, RCS needs to be turned off beforehand.

Texting to iPhones will not use the 'chat' features (no cross-platform RCS is supported on Apple's side), but you shouldn't have issues using regular SMS/MMS to an iPhone. He can try to de-register his number from Google's RCS platform but, again, that shouldn't be causing an issue. Also, chances are you'll see a separate thread to your brother's number since RCS is no longer being used.

This describes how to de-register from Google's RCS:
https://www.androidcentral.com/heres-how--deregister-your-phone-number-google-from-rcs-chat