There is an issue with groups and some skills. If for example, you have set up the everywhere group, for a simple one, you can say, Alexa, play mushroom fm everywhere. It will use Tune in, which can parse the everywhere part back to Amazon and do the deed so you do not get any delays. However many skills, like bbc sounds and others seem not to be able to give Amazon the everywhere or whatever, so an attempt to play Alexa play BBC Radio 2 Everywhere, will only play it on the current device, since the bbc sounds player is unable to let Amazon have the last part of the command. It used to be get roundable by saying on tune in, but since if you are a resident of the UK they have barred uk addresses from being able to access the main national channels through Tunein. It could well be that the spotify skill has the same issue as bbc sounds. The double whammy has occurred not just because the bbc or spotify are stupid, but because of an api change at the Alexa end, that means skills need to be rewritten to work as they used to, implemented to allow the more recent conversation mode of the echos. Interestingly, BBC local radio, and world service are still on tune in, so will lay everywhere.
I've not been able to find out whether anyone is going to fix this anytime soon. Brian