Thank you for the (by now outdated) pretest URL which allowed us to identify the problem.
We do not yet have a complete solution, and sliders still display a bit differently with right-to-left languages. Yet, the issue with the mirrored values should be solved by now.
Please make sure to enter the "0" as "minimum" label and the "100" as "maximum" label, and not the other way around. Otherwise, the numbers will misfit. Also do some tests if the correct number (+1, remeber the coding) is stored in the dataset, please. Just to be sure.