Ribs burnt on the ends

When using my 18.5 inch WSM, I'm having a hard time keeping the outer ribs from getting burnt. I know this is probably from the heat that goes directly up the side around the water pan is hotter than the middle of the grate. The ribs in the middle of the rack are always spot on.

My question is do you also face the same problems and how do you try to avoid this?

For contests, trim your ribs so there are only 9-10 bones. That way, the edge ones don't get burnt. Also ensure you're not cooking higher than 275 degrees. Spray with your favorite liquid after bark forms (about 2-3 hours depending on pit moisture and air humidity).