Can you stand next to your Alexa devices and send over a screenshot of inSSIDer showing your networks in the 2.4 and 5 GHz band? I want to check your signal strength and also see where inSSIDer is finding the mismatch.
Unfortunately there is no way of disabling the 5 GHz on the repeaters which I need because of my Alexa 2.4GHz devices.
Do you need the repeaters because your devices are too far away from your C6 router to establish a connection?