Newbie Mesh Setup

I’m setting up my first Peplink Mesh Network, using a B One router & 4 AP One Enterprise access points. All have the latest firmware. I have created a 5Ghz Mesh ID, all APs are working, but all appear to be communicating only with the B One. The Mesh Network Graph shows a blue dot for the B One and red dots for the APs, with a dotted line from the B One to each AP. Also, the Mesh Link Information shows the signal strengths getting progressively lower as the distance to the AP increases, with the best (closest) being -57 and the worst (farthest) being -87. Also, download rates with my temporary WAN when standing near the closest AP are 105Mbps, down to 8Mbps near the farthest.

Any idea what I’ve done wrong?