@Joseph-TP For Q2, I do not think it was a specific extender. For this instance it was RE-505X, but it could be any one. As of this writing the mesh network is working fine and I would dare not...

I have recently bought BE3600 to replace AX20. I have six extenders, all from TP-Link (3 RE505X, 2 RE305v3, 1 RE300) and OneMesh compatible. I reconnected each of the six extenders to BE3600 and they...