After setting up the bridge and adding ether1 and wlan1 ports. My client gets disconnected (so far so good). Then I disconnect its cable from the switch and it is supposed to stay connected to the AP (bridge) wirelessly but it doesn’t. It becomes unaccessible neither by IP nor by MAC address.
In that manual you have placed online, there is a step you did not, and is add ports that will participate in the bridge.
in the Ports tab do click to Add (+) buttom, add the wlan and eth ports at both sites ap and cpe.