The reason why others can still listen to songs on their mobile phones after handing out wheat:

Open ITUNES, import the song file and the converted movie into the library, then plug in the mobile phone, click the icon on the left to display the mobile phone, and then click' Apply' in the lower right corner to synchronize.

Click Microphone, Voice Settings, Advanced Settings, use karaoke software to mix, and set the mixing source player. This is YY's setting, which should also be suitable for delivering wheat.

Check the mobile phone device to see if some settings conflict, such as firewall, or maybe there is something wrong with the sound device or someone else's device.