That same thing is happening at my house but with a table topper. I went with the monofilament in the top and 'regular' thread in the bobbin. My sewing machine manual said to tighten the tension to #7 (gulp) and turn the bobbin screw counterclockwise 1/4 turn (double gulp). It's working fine! So check out your manual. If you decide to go that way, it may have something about using monofilament.
Edited to add: This particular piece is totally tropical colors and the neutrals just wouldn't have looked good. Besides, it's always good to try new techniques!