Multiple FortiAP's bridge to same SSID

Hi,

I have a FortiWifi 60e and a FAP221C-A.

I have the firewall up and running and the internal wifi set up with an said of "summerhouse" and bridged to the Internal interface.

I've added the FP221c and is shows up and managed in the "Managed FortiAP's tab" 

I now want to add the FP221c as a second access point to the system and use it to broadcast the same ssid.  I'm struggling to understand how to make this work.  If I create a bridge interface I get "Duplicate SSID name exists" when i set the ssid to "summerhouse"

any help would be appreciated 

thanks Karl

I'm using firmware 5.4.1