Nothing new since last call from Linksys support a week ago but it is definitely something wrong with EA9300 if you can’t login with password to your own router on second 5Ghz band. I made some more tests and maybe it seems to be related to WPA2 because it works if you change security mode from WPA2 to WEP or NONE (no password) for second 5Ghz band. Changing other router settings dosen’t make any difference.
Worth nothing but I have a temporary solution that work for me besides resetting everything so if you have this problem:
1. Change security mode to NONE, channel width to AUTO, channel to AUTO and network mode to MIX (this one is important because it is not working every time using network mode as AC-ONLY, even more problems there?).
2. Reboot router.
3. Change only security mode to WPA2.
4. Reboot router again.
5. Now if you followed every step it should work to login on second 5Ghz band with WPA2. then changing network mode to AC-ONLY without rebooting router (it reboots Wifi only) usually works too but there is a big risk that after rebooting router all problems are coming back (sometimes it works even rebooting 2, 3 times but soon or later problems are coming definitely back. Notice that I made all steps with Linksys mobile app, next time I will repeat everything with web UI to eliminate that there is nothing crazy about changing settings with just mobile app or web UI.
If there is not enough with problems I notice also dropping Wifi connection (not internet) on both 5Ghz bands. 2.4Ghz band is fine. Those dropouts are very strange because they are very short (about 1 sec) so many services dosen’t notice this but as example while watching IPTV connection breaks. Watching IPTV on 2.4 band or wired ethernet works fine so those dropouts are not related to internet connection and I have tested this in last 3 weeks with direct connection to router without SMART CONNECT or any repeaters or extenders. Sometimes I’m loosing also connection to my router using Linksys Smart Wi-Fi cloud and this has nothing to do with internet connection because at the same time I can use internet from all of my devices but Linksys Smart Wi-Fi complains about no connection to router.
Right now I have really bad feelings about all of this and I hope that Linksys can sort out all of those problems as soon as possible because EA9300 could be a really good router. Right now is not.