When changing the source of a QSoundEffect I will hear the old and the new sound during the first play() and only the new sound in following play()s. I created a short test project that shows the effect for C++, but I found the same when using QML.
The output.wav shows the effect of issuing
three times in a row. The first occasion is wrong the two others correct.
This only happens on Linux. I tried the code on my Moto G Android phone and everything works as expected