Last week I installed four new foam climbing rings for $10 each. Might have helped with the climbing, but still readily stuck on drain. Yesterday, I removed the tracks (which were hard, not tacky at all, and SLIGHTLY worn) and treated them with 303 UV Protectant (non-toxic, water based), which restored some tackiness. Rinsed them off in the sink, re-installed, and it helped a lot. The thing was frolicking around like new, it seemed happy, but got stuck after an hour or so. Compared to 5 minutes, which is how long it usually took, so I think there is a clue there. I have new tracks on order, but they are taking forever to get here. But that is a $50 spend for the tracks.
My plan is to remove the robot when not in use (so not in the pool 24-7 anymore), and apply the UV stuff every month. And thinking about that 5th brush...