Using ExtraPFL within the Playlist, if you return to an audio item with set markers - and the the +/- buttons (or the mouse scrollwheel), the value of the marker shows all the numbers on top of each other, and does not refresh.
To replicate this, you have to close the ExtraPFL, then return to the item. If you set a “fresh” file with markers - there is no error until you close and re-open the PFL dialog box.