When doing an export and subsequent import, my group MMS chats include my phone number as a recipient. Most messaging apps treat this differently, meaning future messages to that group chat actually create a new one on my phone, without me as a recipient.

Below is an example - the first is a correct group chat between me and three contacts. The second is one incorrectly exported/imported by this app, between me and two contacts.

I tried manually editing the exported data myself to remove my number from __recipient_addresses arrays, which removes most instances of this issue, but some group chats remain this way and I can't figure out why.