The last osage bow I built, actually it was a BBO that had the same problem. I always mark my side taper guidelines on each side of the limbs and never cut lower than my lines. I call these lines the road map for you bows limbs.
Since I started marking these lines I never have a limb dogleg off to the side when a bow is strung, well, almost never.
My last BBO was as even side to side as I could make it, great string tracking unstrung but about 1/4" off with a visible dogleg when strung at normal brace. I suspect a change in wood density on the offending limb where the dogleg started.
A little wood reduction from the weak side had no effect so out comes the heat gun.
I put a little dogleg in the unstrung bow which made the strung limb arrow straight at full brace with perfect string tracking.
Sometimes you gotta' to do what you gotta' do to make a bow, there aren't any rules to follow, just do what works.