Sounds like it was sorted by “most recent” (not the column, but the view mode). That said the Open dialog is a sad sack stand in for even the flawed Finder. 20

Sounds like it was sorted by “most recent” (not the column, but the view mode). That said the Open dialog is a sad sack stand in for even the flawed Finder. 20 year Mac user here: I developed the muscle memory to just have a Finder window open to the file I want so I can drag and drop from that into the Open dialog.