Malfunction while listening

Hello,
I copied a score with personal arrangements.
I sometimes have some problems when I listen to what I have just written.
This problem does not occur regularly!
I have sound breaks as if the device is stuttering. I can hear the metronome beats fine, but they are irregular.
Example: I am in 4/4, pulse 120, first note a quarter note followed by two eighth notes, I hear 4 irregularly spaced eighth notes and the 4 irregular pulses.
I realized that by opening the equalizer which was positioned below the score, this phenomenon disappeared and the reading returned to "normal" as well as the beats of the metronomes.
It seems that there is a malfunction on muscrore 4 because with the previous application I did not have this problem.
Can you give me explanations or/and solutions?
Cordially
JM