Continuous Play of Music Content

[Cornelissen]

My Mede8er MED500X2 Multi Media Player used to play the MP3 's continuously after each other.
Fairly recently, I notice only a single MP3 is played and stop at the end of the lyric automatically.
I need to manually change (circle type icon via the remote) from "1" to "ALL".
Quite irritating as you need to manually do this after each and every music song.
Please advise what the setting is to ensure that all MP3 's are played continuously.