Matches can be won or lost by a point but 505 v 506 is pretty consistent so I wouldn't be too concerned & it's up on your 494 so that's good too. You might feel as if you've begun to plateau a bit but tidying up the errors will pull your scores up. You've identified that you have errors & have a plan to work through them. That's a positive & should show you a benefit pretty quickly when you eliminate them or reduce them.
Pm on its way