Windows app changes iPhone system volume without being connected

[ConorKeane]

Plan

Premium

Country

 Ireland

Device

iPhone 8/Dell Inspiron Laptop

Operating System

iOS12/Windows 10

My Question or Issue

 I have been having an issue recently, every time I change the Spotify in-app volume on my windows machine, it changes the system-wide volume on my iPhone. While this seems to be a handy feature, it's not helpful when I keep my phone muted almost exclusively. I am listening through the windows machine and I do not have Spotify Connect active between the two devices ever.

Sometimes I am able to break the connection by manually closing Spotify on my iPhone, but it reconnects each time I open the Spotify app. 

Could anyone point me in the direction of a setting I can change in order to keep this from happening, or at least a way to make it control volume only when Spotify Connect is active? Has anyone else experienced this issue? 

Many thanks.

[ConorKeane]

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