This seems to be a issue for other Runcast users as well, the developers suggest it is a Garmin not app issue.
Just in case as one guy had a similar problem: how do you try to switch between music providers? This is only possible through settings->music.
Go into music by long press on bottom left button, then options, manage, then music providers. Only Runcasts is showing, despite historically Spotify and my music being available options here.
However…
It may well be, I'm not tech savvy enough to form a judgement one way or another. My comment about the developer saying it is a Garmin issue is taken from recent app reviews where he suggests as such.
From an end user point of view, I'd just like to be able to use Runcasts AND Spotify on my watch ( or have Spotify allow BBC podcasts to be synced).
Go into music by long press on bottom left button, then options, manage, then music providers. Only Runcasts is showing, despite historically Spotify and my music being available options here.
However if I choose your option Spotify and my music are available and accessible.
Thanks