I've seen Amazon sourced devices drop from the 5GHz channel to the 2.4 GHz channel andrefuse to go back to 5Ghz. Even if the 2.4 Ghz channel is shut down. A reboot of the router (Hub2) *and* the devices was required to get them back onto 5GHz. Possibly a side-effect of having the 2.4 and 5 on one name.
I'm of the opinion that a lot of wireless connection problems are property-specific (walls, ceilings and stuff; and coverage, wifi extenders, etc.) and there are lots of specifics which may not be reproduceable.