What are these bumps? Are they fixable?

Hello; you have probably started to gain weight again and in areas, with the least fibrosis; fat accumulation appears to have occurred. The best treatment for that; is Vaserlipo method.

To make an assessment regarding the outcome of any plastic surgery procedure, we generally need to see a complete set of proper before and after pictures.
If you don’t have your before, and after pictures, then try to contact your provider and have them send the pictures they took.
It looks like you have an uneven fat distribution from how the liposuction was done.
People also develop a significant amount of skin redundancy under their back to accommodate the range of motion of the shoulder.
This skin redundancy tends to get worse as we get older with loss of skin elasticity.
The skin on the back has connective tissue attachments to various layers along the back, and this can cause very predictable skin folds on peoples back that are visible when the arm is in a down position.
Many women as they get older and loose skin elasticity will develop a definitive fold just below the bra line. .
These skinfolds tend to look much better when people raise their arms up in the air.
If your provider is within reached and follow up with your plastic surgeon, otherwise consider having a few in person consultations if you want more accurate assessment and possible understanding of treatment options.
Best,Mats Hagstrom MD