And you measured each one individually on a meter?
I find it hard to believe that two coils built the same, with the same number of loops, the same diameter, and the same length of wire, will behave in that manner when fired up. They can't be identical.
The only possibility is the posts are not tight, and you said you checked that.
I wrap my dual coils exactly the same way and check them individually on the meter on the atty. Yeah, its more work that way, but I know they ohm out the same.