'you left the conversation'... only I didn't!

Hello DenaDe,

This is not expected behavior. It sounds like you're off to a good start with the steps you've taken up to this point. Troubleshooting the issue, to further isolate the behavior will be the best course of action. You may want to do the following, and jot down the results. Once you have more information you may want to contact Apple Support directly about this issue.

Try the following:

• See if the issue happens on Wi-Fi, cellular data, or both. This will help isolate the issue to a network, if network related.
• See if the issue is related to a specific carrier or type of device. For example, does it only happen when you're sending iMessages to other iPhones, does it only happen when sending a message to an Android device, etc...
• Does the problem occur when you're in a specific location/address?
• Do you have Screen Time enabled on your device? If so, review your settings to make sure there is nothing blocking your messages from sending. Also reach out your carrier to ensure there are no blocking features enabled from their end that would prevent your messages from sending.

Once you have more information you can contact Apple directly to work with them on resolving the problem. You can reach out to them by clicking here: Contact - Official Apple Support or over the phone by calling the number that is most local to your region: Contact Apple for support and service - Apple Support.

Best wishes!