There is a new icon on upper left of screen that appears to preclude playing a selection through to end, How do I alter. Please make message simple, senior and not adept with electronic devices. The icon looks like two infinity signs.
the sign you are seeing means you have shuffle turned on in the music options. This makes the player play songs in a random order.
PS. you posted in an SSD (Solid state drive) board. Let us know what MP3 player you have so we can have the moderators move your post to the correct board.