Hi,
like the title says, VLC 3.0.5 stops playing an MP3 a few seconds after the screen locks.
When I press the lock button, screen lights up, stays locked and VLC starts playing again (for a few seconds)
This way, VLC is useless as a music player for me.
My phone is an Honor 9 with Android 8.0.
I've set VLC preference Background/PiP mode to Play videos in background and Play videos in Picture-in-picture mode.