Definitely the vle10. Remember the lift ratings are per arm, and with that truck you may be coming close to those ratings. I did a whole pad for my lift. The versymmetric arm design is indeed helpful for some vehicles.
If bleeding it doesnt fix it along with adjusting the synchronizer cables, the issues is with the hydraulics. There is a throttle valve that can get debris in it. Feel free to pm me.
Here is a long wheel base transit with shelving and tools on my CL10V3. No issues with positioning of arms.
https://drive.google.com/file/d/1kYpVcxxBc1XhzGlpE_FdXQAl22oHK4Jk/view?usp=sharing
You didnt say the brand of lift, but most 2 post lifts have control mechanisms in the hydraulics to limit lowering speed of the cylinder. If debris get caught in it, one side will want to go down quicker than the other.
Assuming the anchors have only 3 inches of embedment like you said, I would think it was due to bad concrete/ concrete not thick enough. How confident are you of the thickness?
Assuming the thickness and concrete is fine, fix this with grade 8 all thread and epoxy.