Hello Elizaveta_user,
It appears that you are having an issue playing music from Apple Music.
Start by power cycling the iPhone using these instructions: Restart your iPhone - Apple Support. While simple, this can refresh the iOS, apps and connections.
If you delete the track having the issue, and download it again, does the issue continue?
If it does, tap on Settings > Music and toggle Sync Library off. Wait 15 seconds and then toggle it back on. Keep in mind that it may take several minutes to sync back, especially larger libraries.
Next, sign out and back into Settings > Apple ID > Media & Purchases. Please be aware that this will remove all tracks downloaded to the device. They will need to be downloaded again if needed.
If you continue to have an issue, please post as much information as you can. This will help us all find a solution for you.