What is the bait made out of?
I have the same problem. I am using Resin and I think i may have used too much micro ballons. My first test lures ran great. I made a few more that i put a few more coats of epoxy plus some more microballoons and they swim slow great. But start cranking and they flip!
I am guessing they are too bouyant, ones rises much faster than the second batch. Just a theory, i will know more in a few days.