One may find that automatic aliases are not showing on content where they used to exist. On the content's alias tab you might see the message, "there are no aliases to display." Should that occur, try the below. 

This issue was more common in 9.1 and previous versions. If you experience the issue you can try the following.

1. Go to workarea > settings > configuration > aliasing rules. 
2. Edit and save each automatic aliasing rule.