My Question or Issue
Why s Spotify showing ads on my secondary phone? Spotify is ad-free on my primary phone. Tried reinstalling the app. Didn't help.
It sounds like you might have a secondary account running on your second phone, because, as you said, Premium Plan is free of Ads. I recommend you to check out this article for more information.
If that doesn't help, please send me a screenshot of your screen on your second phone.
Thank you! :)