This is the relevant section of the Sonos manual. I know this begs the question: why did it work before Roon. But I also added the Synology 918+ and a UPS at the same time in the same small space. Hard to isolate but as long as it works I am not going to worry:
If you have a Sonos product wired into your WiFi router, separate the two devices as far as the Ethernet cable between them allows; 1 ft. (30cm) or more is ideal. Also make sure your Sonos system and router are operating on different wireless channels.
Reducing wireless interference - Get Answers about Sonos
https://sonos.custhelp.com/app/answers/detail/a_id/.../~/reducing-wireless-interference