Hi,
New to Draytek and need some assistance with setting up two SSID one for staff and one for guest however guest must not be able to communicate with the staff network.

The devices I have are the Vigor2860ac and the Ap900 which is currently set in the below mode
http://www.draytek.co.uk/support/guides/ap-900-wds-bridge

If I connect to the guest SSID I can still communicate with devices that are on the staff SSID even though I ticked Isolate Member when setting up the SSID - Did I miss anything?
Thanks.

you might find this article useful

http://www.i-helpdesk.com.au/index.php?/Knowledgebase/Article/View/572/0/configuring-draytek-vigor2830-for-limited-guest-wi-fi-access

Piste Basher is correct, you will need to set up the SSID's on two different VLAN's, that is the only way to keep them truly separate.