spotify connect - an unknown device is connecting to my Spotify

[user-removed]

Plan Premium

Country Germany

Device iPhone 7plus

Operating System iOS12

My Question or Issue

 Hi there, I am using Spotify on my iPhone7 and I am using "connect" to connect the iPhone to my MacBook to use the MacBook as a remote control. Now I noticed that some strange and unknown device is using my "connect" too to connect to my iPhone. I see their latest songs played and playlists from this unknown device on my Spotify App on the iPhone. Now I am worried a little bit that this device could have full control to my Spotify on the iPhone .  How could the strange device connect to my system? Does it work via WiFi or Bluetooth?  I already change the WiFi password.  Question: Is there a way to turn off the connect feature in iOS?