This is pretty common when changing cranksets. They often have a different "dish." If so, yes, you may need a longer BB. Measure new and old cranks, from a straight edge across the small chain ring to the inside of the crank arm.

Also verify the front der is installed correctly, at the right height and parallel to the chain rings.

A fellow amateur mechanic showed me a trick, where all that was needed to get a shift was to slightly adjust the rear of the der cage to the center of the bike, just a degree or two off parallel. Not pretty, but it worked.