Some Gmail labels/folders empty (but messages found in search field)

Hi, 

we are testing Em for our Company and we are facing a quiet big issue,

some folders (labels) from Gmail are empty on the Em client side. We can find the message in the search bar, the resultats well show that the messages should be/are in the proper folder, but the folder itself is empty (and of course not empty on the gmial side).

We also have a lot of floders which are complete, lot of mails are missing.

Second problem is frfom calendar, when we delete an event in the calendar it does not delete it on the Google calendar side