Two quick thoughts:

- did you use a BR One BT?

- did you use the Bluetooth pairing-menu or the Remote pairing-menu? They are different and sometimes lead to some confusion.

Using the ip-configuration-page instead of the app might help too..

It's a BT BeoRemote 1 indeed, and tried both through the remote pairing in the app and on the ip interface in a browser on the computer. Sometimes, the BR1BT quickly says 'pairing failed', other times it says nothing for a longer period of time..

I’d try a factory reset of the BR One.

I'm a bit reluctant to do so, as I have completely customized it to my needs. Sources, list entries, names, etc. I use it to control an openhab server with a IR eye receiver, so all sources and settings map to my specific setup (sound, lights, itunes, tv, apps, my fireplace, etc.).

I think I'll just stick with it and try again some time later. I can already control an itunes instance and choose to let it multiroom stream playlists and online radiostations to other airplay devices, so I can easily add support for the new M3s too.

I was curious however to how the B&O ecosystem works with the BR1BT.

Problem solved!

Turned out I paired the remote to my macbook when I bought it, and then deleted the connection from the remote afterwards, but did not tell the macbook to 'forget' the remote. So as soon as I tried to connect the remote to a new device, the mac wanted to reconnect, which didn't work..

So now I paired the BR1BT to both M3s, will check tomorrow what it can do :-).

The BeoRemote One BT also did some updates on itself upon pairing with the M3!

Are you able to use MyButtons with the M3? I cant see any mention of a remote in the user guide

Yes, you can assign certain sources to the buttons.