Description of problem:

When we have a process instance with more than 10 variables and try to navigate though all the variables, the list is not changed. We can't even sort the grid with the variables because it does not work (the sort action is simply ignored).

Version-Release number of selected component (if applicable):
n/a

How reproducible:
always

Steps to Reproduce:
1. Create a process with more than 10 variables
2. Build and deploy it
3. In the process instance screen, click on the process and then on the right side, in the variable list grid
4. Try to go to the second page to see more variables

Actual results:
The grid (or list of variables) will not be updated

Expected results:
The list should allow navigation

Additional info:

Sorting also does not work, but probably this could be a subject for another bugzilla.

I recorded a video that shows what is happening with more details