Are the tracks submitted by individuals tested for bugs? I have a 3 foot coffee table. I entered into "all tracks" and selected one (not entirely sure which one. I don't want to provide inaccurate information). The smaller ball joined the larger one. It appeared as if a magnetic force attracted, and held them together. While "attached", they both began drawing. Frequently, one ball jumped/rolled over the other one, while they still remained "attached". It didn't appear correct. Turning the power off did not result in the smaller ball returning to its proper position. Both balls remained together, touching each other. I had to remove the cover glass and manually return the smaller ball to its proper resting position. Any thoughts?
Hard to know what was the specific cause of both balls being together - but almost certainly could not be related to which track you played. More likely, sand may have built up around the "ball-park" (barrier under the shade ring where the second ball is parked and picked up). This can prevent the second ball from going all the way into the park - if so, it can accidentally be picked up by the main ball as it goes by. There's no automated way of separating them - so the fix is removing the glass and doing it manually. Make sure you brush the sand around the ball-park to remove and build up. 2-ball mode is still somewhat new, and we're working on optimization to prevent this.
Just letting you know I saw this behavior too. I ended up removing any playlist that activates two balls for this reason.
One theory I had was if the table loses power or is rebooted for some reason while in two ball mode, I suspect it goes back home and doesn't have the 2nd magnet activated - which means the 2nd ball is left behind and may get picked up with the 1st magnet causing this problem. In my case it definitely wasn't sand build up.
In any event, seemed like the safest course of action was to just remove the 2nd ball activating patterns until the corner cases are a bit more supported.
As @dithermaster says, both magnets are permanent. @sisyphus5 - when the table reboots (for any reason), the first thing it does is go home, and then it parks the second ball - since it doesn't know whether it's attached or not (and a "phantom" parking does no harm). We're still actively working on "hardening" 2-ball mode so it is more reliable in avoiding 2-balls on one magnet.