We are experiencing some strange behavior on our Drupal 8 website with url aliases.
All our nodes in the site have automatically generated URL aliases based on a pattern.
From time to time, a node loses its URL alias making it only accessible via /node/id. When we edit such a node, the checkbox for automatically generating an alias is still checked, but there's no value there. And when we save the node, the alias is regenerated and the problem seems to be fixed. But then the same happened to other nodes on other moments, and it keeps happening.
I haven't managed to reproduce the problem since I don't know what triggers it. I have tried several things, none seem to work.
For these faulty nodes, the URL aliases are no longer in the database (or never have been there).
Our client tells us it also happens to nodes that haven't been touched in weeks.
I'm using Pathauto 8.x-1.0-beta1 and Drupal 8.2.3.
Does anyone have an idea what might be happening?