sinking music with audio

Hello, 

I am hoping someone can help me. I instruct classes via Zoom but continually have problems with sinking my music and voice.  The majority of the time they can not hear me or the music , the music is going in and out, my voices is going in and out . Any suggestion would be helpful regarding setting or connection. I have tried playing the music off my blue tooth off the computer and still having issues. 

Thanks in advance.