The SR2 is in AP Bridge mode and everytime you reboot, loose power or apply a new setting the clients rarely reassociate without diabling and renabling the wireless interface several times. When I say several times I mean 10 to 200 times before clients come back online.
We run both Cisco 1300 APs and MikroTik R532+RouterOS 2.9.24-based APs. We have not seen the problem you describe with Tranzeo CPEs. IIRC we did notice that CPQs had to be returned to factory default values of RTS and Fragmentation Threshold.
Are your CPEs at the current revision level?