Hi @BAGTAG,
We’d need to look into how the network is set up in your office. Spotify Connect will show devices on the same network, so if Spotify can’t find those devices, it generally means a network issue,
Do you know how your office network is configured? Are there multiple access points, a mesh network, a switch, or any additional networking devices in place? As you also mentioned you can see 1 other speaker in the Sonos app (I assume 2 of the 3 devices), I’d recommend submitting a diagnostics and replying here with the confirmation number so I can have a look into the Sonos system.
Office networks can differ from your average home network and may have more networking equipment, so we’ll want to ensure that your office network meets our system requirements and isn’t an unsupported setup.
I hope this information helps!