With a directory in the left pane, I assume you’re refering to a cluster (which can be equivalent to a directory, depending on your file naming script)? Or do you use the file browser pane, which shows you the folder structure on your hard drive (can be switched on/off under View)?
For option 1 (clusters): right click on a column name at the top of the pane, tick the box in front of Album and then click left on the Album column. If you now create a cluster, the tracks should be in the correct order. (This doesn’t change the sorting order for clusters created before the album column was activate, since all tracks in the cluster will have the same album name. Uncluster/recluster them to resolve this.)
For option 2 (folders): these are the actual files on your hard drive, sorted in alphabetical order. If these changed order after you installed the last update, you might have lost your file naming script in the process.