Samsung Galaxy S9
When my phone is connected to my car via bluetooth and I let it sleep or change apps. If I re open Spotify the song will skip forward ~2 minutes into the current song. So if the song is halfway through it will just skip to the next song, or if it's at the beginning it'll skip to the middle or near the end of the song. I haven't noticed it doing this when using bluetooth headphones on wifi or data. So far it's just been in the car.