Help RCS Messaging intermittent

Try a different messaging app from the play store, such as Textra, which supports RCS. I've been using it for years

Textra is a fabulous app, I've been using it since forever. It's very reliable and offers a ton of customization, I've had no issues with it. It now supports iPhone reactions but does not use RCS, as soon as Google lets them they will though. As far as I know no one but Google can use RCS.

I'm just going to play devil's advocate here and rail against RCS for the following reasons

-- It's a proprietary protocol, and it's licensed by Google. Google has a history of failing to provide long-term support for its own products so if for whatever reasons it decides that continuing to support RCS isn't worth the bother, don't be surprised when it gets axed.
https://killedbygoogle.com/

-- Google's track record on text messaging in general has been a bizarre mix of failed products and standards. It will be surprising if RCS is going to be the one standout that breaks a trend.
https://arstechnica.com/gadgets/202...ability-the-history-of-google-messaging-apps/

-- Despite Google's push to make RCS the Android text messaging default standard, it's still not universally supported throughout the Android market. Add in that Apple refuses to allow support for RCS into its iMessage app and that makes RCS just one more of multiple other proprietary text messaging protocols. SMS/MMS are dated and antiquated but they're still the only two protocols every text messaging service and carrier will implement.

So your battle to get RCS working consistently again on that OnePlus phone could be a multi-layered problem. Given all the things you've tried, it sounds like a network connectivity issue but even that is iffy since things were apparently OK previously and then went bad for some reason. Don't forget while SMS is such a low bandwidth protocol it can travel across just basic cellular connections, but MMS requires at least mobile data (or WiFi) bandwidth, the issue being RCS is more like MMS in this aspect.

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You should follow these tips:

• First check the internet connection is working fine.
• Update your Google Message app.
• Check the RCS status from Settings.
• Switch from cellular data to Wi-Fi.
• Disable Chat feature on your previous phone. For this, open the Messages app and then hit on three dots. Next, tap on Settings > Chat feature. Lastly, toggle off “Enable chat features”.
• Reset the network settings of your device.

All these solutions has been taken from RCS (Google Messages) not working on Android. So, if the above methods didn’t help then you can follow other tips from this article.