Was your latest DXA scan done on the same machine as the previous one?
If no, maybe that's the reason for results showing no change? (DXA's need to be performed on same machine to provide apples-to-apples comparison.)
If yes, ask for both of your DXA results to be reviewed again, in case you were not properly positioned on the machine, radiologist read scan incorrectly, etc.? Keith McCormick's "Great Bones" book and Lani Simpson's book go into detail about these and other DXA errors.