Polaris robot leaving black marks?

[NaCLTPool]

It looks like my robot is leaving black marks / tread marks around my pool. Anyone know the reason for this or how to remove?

 

[wireform]

The first thing to check is if both tracks move freely or is one of them binding. Also see if maybe the rubber on one side is sort of sticky like the rubber is degrading.

 

[NaCLTPool]

The first thing to check is if both tracks move freely or is one of them binding. Also see if maybe the rubber on one side is sort of sticky like the rubber is degrading.

Robot is only 3-4 months old. Tracks are moving freely and I can’t tell of any sticky rubber. I will inspect it a little more closely just to make sure.

Any tips on how to remove from the fiberglass?