Tado - different setup experience on Docker or Pi

I’ve got this repeatable problem with the Tado integration that I can’t get to the bottom of. It may even be a bug but (1) I can’t see how since its the same code and (2) nothing in the logs indicating anything like a communication error.

As I said, this is completely reproducible for me. If I add the Tado integration on a Docker install of HAss I get this window

But if do the same thing on a Pi install I get this

Which is the Tado identifier for device.

Has anyone else seen this? I’ve tried on a 3B+ and a 4 and get the same result.

Thanks

Steve