BBA's Marble Rye cracks during fermentation

Hi,

I am facing a problem with BBA's Marble Rye swirl design.

After mixing the dark and light mixtures and fermenting them for 90 minutes, I created two A4 size sheets of dough and then put the dark rye sheet over the light one.

I rolled the two sheets together and put them in the tin pan, covered with plastic.

After about 45 minutes of final fermentation the top light rye layer got cracked and torn by the layers of dought under it, pushing it upwards.

The bread comes out very airy and tasty, but the crust is all torn apart.

I baked this bread twice, and it happened in both cases.

I thought of creating my own cut to ease the pressure and let it rise easily, but I am not sure if this is the best way to solve the problem.

Any ideas?

Thanks,

Shai