Cleaning it after every session?

In my experience that's fairly normal. It definitely varies from ball to ball but some get that visible track in them early on.

Ball has got a good track on it already with only 20 games.  Wondering if that is normal.  Only bowling on synthetic lanes.

So, do synthetic lanes never wear the surface of a polished ball? No, of course, not.
Most polished balls will show noticeable wear between 9 & 12 games. Sometimes as little as 3 games, EVEN on synthetics.
Your ball needs to be repolished, NOW.
I also suggest you keep a closer eye on your track AND the ball reaction.

PLUS,
sometime between 20 and 40 games, you need to redo the whole surface, from scratch, starting with 500 grit and working your way back up to whatever is "polished" for you.