A 44DD is a 44 band with a DD cup — a fuller cup. The band does most of the work (around 80% of your support), so if it rides up at the back or the straps dig in, it's the band to fix, not you.
We cut 44DD for fuller busts, part of our full 44D–44K range. Not sure 44DD is your size? Book a personalized fitting and we'll get it sorted.