The film is versatile and Thomas is right.
I use Xtol 1+1 for contrast, and PMK when I want to tame the contrast.
If the lack of contrast and flat diagnosis is from scanning, that means you are not completing the computer process which involves shaping the curve in image editing software. Raw scans look a little flat, but it's easy to fix. The same negatives print wonderful though in the darkroom. Then it's clearly a computer process issue rather than a film or chemical issue.
I have no idea what caused bands/layers for the OP without looking at the negs.