I've got an RT-AC86U in Access Point(AP) mode / AiMesh Router in AP mode, and an RT-AC68U in AiMesh mode. From the 86U I can discover the 68U. Trying to add the AiMesh node 68U, the 86U counts up slowly to 52% and then rapidly climbs to 100% and reports failure. I tied the troubleshooting steps: waiting and trying again, check that firmware is latest, ensure node is within 3m of master router. Hone made a difference. Any suggestions?