Found an annoying interaction after spending hours trying (and failing) to connect my Sonos One to Alexa:
Attempting step one of the Alexa set up through the voice services menu in the Sonos app would result in an error message when trying to link my Amazon and Sonos accounts.
Found out that this was to do with my phone's default diversion to the Amazon shopping app for all things Amazon (Must have clicked "Always" at some point when being redirected to the Amazon app).
Solved this by uninstalling the Amazon shopping app (and the Alexa app for good measure) and retrying the voice services procedure. Before uninstalling Amazon, I wouldn't get past the first step. After uninstalling, it was all seamless.
Hope this helps someone with a similar issue. Amazon really should provide this sort of guidance but I found nothing.