two calenders on iWatch

Dear Apple Support Team.

I have a new iWatch and unfortunately I’m not really happy with it….

Iphone 6 and iWatch are both running with newest Software.

I have an Mail/Calender Account from google and a mail/calender account running on Exchange. Both accounts work with mails & calender entries perfectly on my phone.

Regarding my iWatch the calender is not working. Depends on my settings I get only one calener synchronized to my watch – but never both. After switching on/off of my watch, there is then an other calender. New calender entries on the watch are not synchronized to the phone… Some how, but don’t ask how – I got yesterday managed to get calender entries out of both accounts on my watch. But it was only a singular synchronization. After this, new entries have not been synchronized any more…

What can I do? How do my settings have to look like to get it wrong…

With this setup, the watch is unuasable for me 😟

Thanks, George