"Popping sound" issue when breaking one sound effect and starting another

Hello, community!

I wanted to ask help regarding strange sound effect i hear during investigation of possibilities for my game.

So in my game I have a control over some sounds with the keyboard.
For example by pressing “e” the flute in a game plays some note.
If press and hold it for 5 secs the whole sound file is played.
If I release it sound should stop playing.
Till this point everything is OK.

But the problem is when I want to press it like few times in a row.
The sound is making “pop” effect every time I break previos melody and start new one.

Guys, do you know if I can do anything with that? Any ideas?
I will appreciate any help! Thank you!

P.S. I checked Audacity and the are no any peaks in this sound.
P.P.S. I don’t know how to attach zip with sample to this post.