Following the reset, your hub is broadcasting the 2.4 and 5ghz networks with the same name..
You can log into the hub on http://192.168.0.1 - browse to advanced -> wireless and rename the two networks in there (add a _2 and a _5 or whatever they were before)
whilst you're there, you should also disable channel optimisation (advanced -> wireless -> smart wifi)
then save/reboot and it should come back up as before.
as for "will it make a difference" - it certainly seems to for some people - give it a go and see.