Multiple audio in imovie 10.1.8, mic sound lowers while music is higher

I have a video with microphone audio, and a music video with audio track. I want to combine both to create a single video.

However, when the music video and the audio from the mic overlap, the sound of the mic goes down a lot and the sound of the music video comes up. I tried changing the volume level of the mic audio higher and lowered the volume level of the music video but whenever I decrease the volume of music video, the microphone audio sound goes down as well. It gets muffled and sounds less than what it should be. Once the audio from the music video finishes, the audo from the mic pops back up. It's as if it's muffled while the audio from music video is playing and then gets the full sound once the second source of audio is done.

is there a way to make the mic voice higher and music video audio lower so when I talk during the music video, the sound isn't muffled?