I am using a RUTM30 in passthrough mode (to my router).
WIFI is off, no VLAN, most settings left to factory default.
On my Mac the Spotify app does not load as it does not get an internet connection.
When I use another 5G router Spotify works.
When I connect my Mac via my cellular Spotify works, too.
So it seems to have to do something with the RUTM that is blocking.
Thanks.