I would suspect that as the OP purchased it ‘on vacation’, they probably ignored the fact that it requires being set up on WiFi before it can be used.
As indicated in the marketing materials (and likely on the box as well, but I don’t have one to hand):
Will Roam work with Bluetooth out of the box?
Like all Sonos speakers, Roam must be set up with the Sonos app while on WiFi before you can connect a device directly via Bluetooth.
However, I’d assume the same applies to AirPlay 2 as well. Essentially, I feel like the speaker needs to be initIalized with an OS, so it can function.