Problem 2 streams playing at same time

So I got a pi2 and managed to link my pc hard drive music folder in the volumio app, and spotify also works.
My issue is that whenever I am listening to Spotify and turn volume up or down, using my phones volume buttons, a song from my pc hard drive also starts to play, at the same time.

I am in no way technical, it was a major achievement for me to even get this far, so please go easy on me, I am trying my best and I really hope you can help, thank you.
I also don’t know how to access volumio from my desktop computer, I think there is a local Web address I need but cannot figure that out either.

Whatever you called your Volumio is what goes in the browser address bar. The default is Volumio.
So, volumio.local would be fairly typical.
You could also use the IP address of the Volumio. Look in Settings, Network.
Then put 192.168.x.x or whatever your home network range is. EG.

Thank you for the reply, appreciate it, I can now access it using the ip listed in settings!

Any ideas on how to fix the two streams playing at same time?

I have no idea how the two streams thing is possible or happening, sorry.

It seems like your PC could be pushing the audio files to Volumio over UPnP. I find that Windows does many of these helpful-not-helpful things all the time.

Go into Volumio settings and click Sources. Under Functionalities Control, click the switch next to UPNP Renderer so that it is Inactive.