exchange calendar delegation

I can t see the other calendars in em client although I have them in my delegation list.
I tried repair, but nothing happens.
In Delegation giving other users rights also is out of function. You can set them and next time when you open it, its gone.

Hello Christian,
what version of eM Client does this happen on? Help>About.
Which account does the calendar belong to?

Regards,
Olivia