Switching devices changes song

[Azaleus]

Hello all,

Spotify has been working without the singlest issue, with my premium account, for about two years. But for the last two months though something came up. 

I have an old PC (windows XP) which is connected to my TV and i often use it to play music/spotify. 

The problem is when I listen to a song on my phone/laptop and I switch to the PC, it plays a song from the same playlist but about 50 songs higher in the same list. 

The problem doesn't exist when i switch between two other devices, and there is no problem when I directly use the PC without switching. 
It used to work perfectly, I did no update or anything.