Hello @Marcin1234 and welcome to the community!
Start troubleshooting by doing the following:
1. Try other headphones on your phone, if they are still not working try the next step.
2. Clear the cache of your Smart Connect app:
- Go to Settings -> Apps -> Smart Connect -> Force stop, Uninstall updates, then go to Storage -> Clear data and restart your phone.
- Go to your Play Store and update Smart Connect again.
