So, I did a private checkout of OOTB rule from UI Gallery and added a few columns. I resized the browser so that I see the horizontal scroll bar. The filter popup appears fine for me (both left and right).
Hi! Thank you for your help. I get the same issue with IE. Last Friday I joined a screen sharing session with Pega support. The colleague from Pega side couldn't find or reproduce the reason of the issue, too. I'll do some further tests regarding harness and portal.
Unfortunately Pega support could not reproduce the problem. At the moment we are checking our implementation of the section. From my point of view the problem appears when standard repeating grid is being expanded with additional columns until horizontal scroll bar appears. I'll do some tests on our side and let you know about the result.
Please excuse my late response. Unfortunately we were not able to fix the issue by ourselves. Customer decided then to reduce the number of columns of the repeating grid. Therefore no longer the horizontal scroll bar appears within our solution.
But from my point of view the reason for the problem must be the calculation of the position of pop ups which uses an absolute value based on the browsers display resolution. But when the repeating grid is larger than the browser window the position of pop ups must be recalculated by PRPC.