Ball sometimes get stuck...

...when it reaches the top-right of the playfield. Not each time... but seemingly ad random. It'll be stuck there vibrating like some sextoy. Nudging the table releases it again, so it's no biggie, but it does take some of the table's shine off.

If you're talking about the area immediately in front of the right-hand Release target, there's a magnet under the field that holds the ball there for a few seconds while you collect bonus (because you hit the target when the Collect Bonus arrow was lit).

Is that the vibrating ball you're talking about?

Yeah, not a bug. Wait a few seconds

Facepalm time. I guess I'm used to a table producing a buzznoice for show when it magnalocks a ball.