I do a "Compare Folders, Select newest" and:
(1) exactly the same file, with the same size and date, shows up selected in both panes (neither should be?),
(2) exactly the same file, with the same size and date, is selected in one pane and not the other (neither should be?),
(3) I would have expected, based on the documentation, only files in common with both left and right pane to be a candidate for selection, but left-pane and right-pane only files are also selected.
See attached screen image.
The on-line doco:
Compare Folders, Select Newest
Will find files/folder that exist in both panels and select only the newest of them.