interaction between audio tracks

am recording a 5 track podcast.

track 5 is music outro.

track 4 is announcer outro.

track 5 begins before track 4.

when track 4 begins, track 5 goes silent.

this has never happened before and is unwanted.

earlier same thing happened with tracks 1 & 2.

track 1 is music intro;

track 2 is announcer intro.

as track 2 began, track 1 went silent.

corrected before by deleting and redoing 1 7 2 but something seems amiss.

how do i correct this issue.