Need help quilting over thick seams

Ceil J

I really do want to quilt this using a design I bought from Designs by JuJu.  It's cute and perfect but I cannot get it to stitch out without a mess on the back (see photos) due to my thick seams.  In my defense, I did follow the pressing instructions to the letter from the Fat Quarter Shop.  This is their free Bats and Boos quilt. 
I am using the blue dot case, purple tip needle, tried a size 14 non stitch needle and nothing seems to help.  When I stitch it out on a flat sample piece it works fine but whenever a critical part of the quilting pattern hits one of my bulky seams, it seems to pull the upper thread to the bottom in a long loop.  It even cut the thread once.  I really do want to use the continuous pattern but am not sure how to fix this.  I have done what I can to further flatten the seams and have stitched this out AND removed all stitches 3 times.  I really don't want to try again without some advice.  The bat's eyes in the pattern use very small stitches but that's not always the problem.  I do have Hatch so I can try to alter the stitch size but that's gotten me in trouble before.  The black back photo was taken when I was using a yellow dot bobbin but the long threads are still the same.)
Any advice would be appreciated.

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