On my S7 I have a high volume MMS group text with mixed devices (Droid/ iPhone) I encounter a number of issues when texts come in rapidly. The Message+ app would occasionally lock up so you could not send or receive. Uninstall reinstall fixes that but it became a hassle due to the time involved and the frequency with which it occurred.
Switching to Messages from Google and disabling Message+ seemed to work for a bit but I see the following now (with greater frequency)
- Texts will show as the individual user not the group
- They will display/play notifications even when notifications are turned off for the app, the individual, and the group (to the point I must silence the phone)
- They show as "Tap to Download" which may or may not work ... often they say unavailable or expired when they just came in a moment ago
- Eventually Messages too will lock up, requiring a removal/reinstall
It only happens with the one group, deleting the group does seem to make a difference, clearing cache didn't seem to help, rebooting either.