Reccuring meeting multiple updates not showing correctly on Iphone

We use IPhone 5s on IOS 8.1.1 with Exchange 2010

A user create a recurring meeting in his Calendar using Outlook, the meeting show up correctly on the Iphone for all occurrences

The user modifies one of the occurrence of the meeting using Outlook, the meeting occurrence that was modified shows up correctly on the IPhone

The user modifies the same occurrence once again using Outlook, the meeting occurrence does not get updated on the iPhone and shows the meeting how it was modified the first time.

When I look at the sync logs that are generated by the Exchange server I can see that the changes made to the meeting are being pushed to the IPhone, It just looks like the phone cannot render it correctly.

This problem is 100% reproducible, in our environment.

Anybody else has experienced this or can reproduce it?

Marc