When using fixed columns, there is a problem when a row within that column has to be wrapped due to size. If the table scroll bar is all the way left the “tall” row is fine. However, when the scroll bar is slide to the right and the bar goes far enough to reload the grid, I assume for chunking, it resets the the row height to a normal size causing a misalignment after the fixed columns. If you scroll back, where it “re-chunks” again, it is fine.
Here is a JSFiddle showing the bug. After running, go down to B3 and enter “This is too wide”. This should cause the row height for row 3 to increase. The rest of the row’s height increases with it. Now, scroll the grid window to the right and eventually the grid will reload causing the row height on the right to collapse causing a misalignment.