ios 8.4: unable to open outlook meeting calendar invites

Another issue with 8.4.

Prior to upgrading to ios 8.4 when I received outlook meeting invites on my phone I could open the mime attachment and see the invite. There was a small bug that would not allow me to accept the invites (it said this invite is managed by your delegate) but I could work around it by going to the calendar and accepting the invite that way.

Now in 8.4 the outlook invite is attached to the email but clicking on it does nothing.

This is clearly a down-grade. Frustrating.

Summary of issues I have identified with 8.4

1) much diminished AT&T signal strength -- to a point where I am getting "no service" in areas I used to have reasonable signal

2) no ability to open Microsoft outlook meeting invitations emailed to me

3) no siri over cellular

4) no find my iphone on cellular

5) no connection to icloud over cellular

thoughts people? (yes, I have tried hard reset).