Strange delay before playing a sound after another sound has finished playing

[Lebostein]

I have s simple circuit with an Arduino Nano, a DFPlayer and 3 buttons. Button 1 calls playMp3FolderTrack(1), Button 2 calls playMp3FolderTrack(2) and button 3 calls stop(). Sounds 1 and 2 are very short (3 seconds each).

If I press button 1, the sound 1 is played immediately without delay. If the sound has finished and I press button 1 again or button 2 then the next sound is played with a delay of 0,5 - 1 seconds. Very anoying.

But: If I press button 3 (=stop) after a sound has finished playing, then the next sound is played immediately without delay, like the first after starting the program.

What is going on?

[Makuna]

Reminder, issues area is for tracking bugs, this part of the wiki directs you to discussion area where this now was moved.

Sample Sketch that demonstrates what you are seeing?

Turn on Debug Feature and include the output.