Found this forum linked from a Sonos page where multiple people have identified this same issue. The update on 4th May however has not resolved the issues for me, I am still having inconsistent results between 2.4 and 5ghz devices which is causing me massive issues. Those of you that have got everything working are you on the v0.26.04.04227-BT firmware please or are the techs on this page pushing you a different one ?
Your issues sound very much like mine. It has been 48 hrs with the updated firmware and so far, so good (see my post from yesterday). BT just send the firmware to your SH2 and tell you when they've done it. Reboot the router, test and check whether your connectivity issues happen and if they don't reoccur then hopefully that should be it. Am still checking it over and so far I connect to the 2.4GHz devices every time, especially when I see my phone is on the 5GHz band at the time. Hope it solves your issue.
I was given the v0.26.04.04227-BT firmware and it seems to be an improvement here. Mind you it has been only 48 hours. I'm using a Samsung phone that jumps from 2.4GHz to 5GHz as I move around the house, and it has the Sonos app. Sonos speakers use Spotify and are on the 2.4GHz band. Are you seeing the exact same issues as before? For example for me, as soon as my phone went onto the 5GHz band, the Sonos app would not be able to connect to or control the speakers, (example attached below what used to happen a lot).
I received 0.26.04.04227 firmware overnight and this morning I seem to be able to consistently connect to my SONOS devices from my iPhone, iPad, MacBook so far with no issues. I also seem to have a mix of WiFi devices connected to both the 5GHz and 2GHz bands as expected. WiFi speed seem as expected too.
Some people on here mentioned Epson printers, I also did a wireless test print from iPhone to Epson WF-2830 and worked ok. Not printed anything for a while so no idea if this was working before or not.
Early days, but looking good so far and will post here again if anything changes.
NB - I still have smart setup off (although I'm not sure what it does).
@B3NNYB0Y . Pretty much the same. I currently have had to resort to a cabled connection for my sonos system. I can work around by turning off the 5ghz band and everything works perfectly as it did before the update on 11th april, but obviously that is not a permanent fix. I can't even print from my laptop to my wireless HP printer effectively and my smart sockets either don't work or are incredibly slow