Spotify not connecting on Bluesound anymore

[simonsde]

Plan: Spotify Family

Country: Netherlands

Devices: iPhone 6S, 7 and 8

Operating System: iOS latest version

My Question or Issue

Since several weeks, my Bluesound devices are not visible on Spotify, so I can't connect my speakers to Spotify anymore. The only short-term fix is to delete the app and reinstall. The speakers will be visible for a maximum of a day, after which they disappear. I have followed all recommendations from the Bluesound helpdesk, but nothing to solve the problem. I am reaching out to you now as I am considering cancelling Spotify and move to Tidal as that works as it should. Can you help me out? Any help is much appreciated.