Vitto, it sounds more like dirty track. Run a voltmeter probe along the length of the section to check voltage along the way. If it changes up and down that is a pretty good indication of something on the track. If the voltage only decreases as you move away from the feed, it would be more likely in the rail connections. The bad connection can be either on the power or the neutral side (red/black),
Under transformer control, a drop in voltage can trigger the directional control to switch from forward to reverse (it does not need to go to zero). Of course there are other gremlins which can cause similar issues - the worst is an intermittent bad connection.
I used painters tape to cover my rails while I was laying in scenery. The residual tape glue was surprisingly enough to create similar issues,
