Problem:
House in Woodway was using older router that was also supplying WiFi using WEP for security. WEP is now insecure and should be replaced with WPA.
Occupants ordered a TP-Link router to replace the older router to provide WPA.
The new router could not easily be converted into an access point. When used as a router, the computers were not able to connect to the Sonos sound system.
Solution:
Recommendation was to replace the old router (working as an access point) with a real dual-band access point (not router). The dual-band ability would provide more device capacity and allow the computers to connect to the Sonos sound system.