It's hardly original (no way)

Try to use TTS, but even then problems can occur
But, this has been discussed many times. Causes - the device itself, ie the system/launcher ... energy saving policies - working in background, permissions, some internal software (cleaner or whatever), driver problem (device related) etc etc
check everything carefully, you can change the sound channel on which the application communicates. Try to find it yourself on the forum, in proper section