BTW, the "Contact Customer Care" link to "Contact Us" goes to a dead link (https://sonos.custhelp.com/app/ask).
Diagnostic #: 1368269781
Best answer by Chris
I would try on iPhone 7 on its setting delete you wifi (forget network) reboot router and sonos and add wifi back to phone (even see if can connect to a 5ghz signal vs. regular). See if that helps.