Odd, I updated a couple of hours ago from the iOS store, and have had no issues at all.
If you’re unwilling to call Sonos Support directly to discuss it, I’d suggest a couple of things. Not sure if it is the controller app, or last week’s firmware update, but I’d try a couple of things.
First, I’d delete the controller completely from my iOS device. Then I would hard reboot the iOS device, just to clear any lingering memory issues. I’d double check for any Apple updates to iOS and apply them. Finally, I’d try a fresh download of the app from the iOS ‘store’, and re install the app. If presented with the option, always select ‘Connect to existing system’.
If it’s firmware on the speakers you’re experiencing trouble with, I’d just walk away for half an hour, then check again. I’ve noticed with some updates that the ‘process’ in the controller can ‘finish’ before the actual process completes on my speakers, and if I just wait, the process finishes, and when I ‘check for updates’, it finally tells me that no updates are necessary.