Your lines look pretty uniform. Any chance you've actually measured the distance between them?
I'd think if you had a bent blade you wouldn't end up with nice straight lines like that. Is it possible that a tire is bending the grass down and you aren't getting enough suction/lift from your blade to stand it back up and cut it off? It may come back up on it's own after a few minutes....
2014 2032R tractor/H130 FEL w/Bolt-On Hooks/54" Snow Plow/iMatch Quick-Hitch/County Line 5' Scraper blade/County Line Carry-All/Artillian 42" Forks & QH Adapter/JD Ballast Box/Frontier SB1164 3PH Blower/Leinbach PHD/Wallenstien BX42 Chipper
Have a x540 cuts nice and straight Check tire pressure deck level blades
level the blades NOT the deck. Throw that deck leveling tool away. Also, check tire pressure and make sure gauge wheels are set proper.
I had an issue with my 318 where one of the blades was lower than the rest. Depending how much you over hang the passes you might be causing the stripe.
You can take a look at the pictures here.
My brand new 530 did the same thing the deck spindles were misaligned ie not parallel from the factory ..cut a stepped lawn and it looked like crap...tried to explain to my local dealer whose service tech stands in as the village idiot..(don't get me started)..ended up removing the deck and spending a half a day realigning the spindles myself (it involves metal work)and it cut's a putting green lawn now..that said I suggest getting a new replacement deck if you can ..under warranty