Hello @banan811 ,
Welcome to the spotify Community!
By any chance would the "publish my activiety" option be toggled off? listening in a private session does turn this option off automatically. Make sure on both your phone and your computer that this option is toggled on so that your friends can see what youre listening too. If this option is on, I can suggest logging out, restarting your device, followed by logging back in again. If the issue still persists from there, try doing a fresh reinstall of the app on your devices. Follow these steps for the reinstall.
Hope this helps, Happy Listening!