In three of the dozen or so grids in our applications we have an issue with Shift DownArrow and ShiftUpArrow in the grid. When used, these operations select two additional rows, not one as expected. This happens only in the grids which have DisjunctRowSelect. In one case, the grid is not set to extend the selection on shift up/down, but the selected row still moves two rows with the shift key down, instead of one.
After some debugging and detailed analysis of differences between the previous version of Advgrid we were using (marked as 8.3.236 but I think 8.3.2.6) and the one we have switched to (8.3.5.0), I identified the addition of "inherited" on line 55098 of the latter file as a possible culprit. Indeed commenting out this line solves the problem, and it appears has no other detrimental effect in our applications.
I do not have time to research this bug further, and I am sure that there is a good intention in adding the 'inherited', but it breaks the shift click up/down in our applications, and the removal fixes it. I am confident that you will come up with a solution that also works for the intended purpose of this line of code!
This is an excellent example of the usefulness of the rule we have always adhered to for many years: never allow the TMS installer to remove the only active working copy of the previous source code!