I'm not a fan of Rodinal type developers for faster films, though Rodinal is my standard developer for slower varieties. It emphasises the grain in a mushy, clumpy way in my experience - I'm not a chemist, I simply go by appearances and experimentation so I can't tell you why this should be. The film appears to be overexposed, the edge rebate data seems okay so it's probably not an overdevelopment problem, though it may be slightly so. This will add to the greyness of the images. The grain looks slightly out of focus in places which suggests the film isn't lying flat and adds to the general mushiness. Tri-X uses a thinner film base than Ilford and Foma, and it's an absolute swine to keep flat in a scanner. Make sure your lens and filter are clean, greasy fingers on front or rear elements, or internal fungus will radically reduce contrast.
Getting the correct exposure, film, developer, time and agitation combination requires a bit of experiment, remove one variable at a time or you won't know what's the offending factor. Once you've done your homework you should be getting crisp, contrasty, easily printed or scanned negatives every time.