I don't know if this helpful, but this is a common problem on Jeep JKs (front disks). The resolution is replacing the rubber brake lines going from the steel brake line to the caliper. The theory is that the rubber line is somewhat internally collapsed, works good enough when you push the fluid via the brake pedal. But the fluid can not recede enough by itself because of the reduced internal diameter of the rubber brake line. Anyway that is the theory, in practice it solved the problem on my Jeep and many others who had the same problem. So this may be something to explore if you can't find any other causes.
don
