I had very similar track-skp problems, and also random noises varying from whiteish to sounding like a skidding needle on a record on one channel at a time for a fraction of a second. I was running Rockbox 3.14 stable release on a Sansa Clip+ purchased in late 2017.
This thread on the Rockbox forum starts on another issue, but starting with reply #11 it discusses my problem: http://forums.rockbox.org/index.php/topic,52044.0.html. The developer Saratoga suggested that a new battery saving adjustment might be at fault, and provided an older Version 1015088, which appears to have solved the problem. I’ve run for 2 weeks without noticing a glitch. Since the glitches seemed random I can’t be totally sure of success.
