Calendar errors and sync problems after ios9

I'm a Google Apps for Business user and sync mail, calendar and contacts (setup as an MS Exchange account) to my IPhone6. All kinds of sync problems started since the ios9 upgrade. Synvng in both directions have problems. So I installed the Google calendar app. This works fine for a while - but several recurring appointments (including birthdays) are being messed up.

I had calendar items automatically created for birthdays and anniversaries in the wrong month!! For ex on Sep 30 th I had an anniversary show up on my calendar for someone whose anniversary is actually Oct 31st.

I saw a few other posts with sync problems. But no mention of the recurring appointment issue.