some assignment types do not seem to accept user tours. This has been identified on our own 4.1.4 site, but we've tried validating on the moodle demo site https://school.moodledemo.net/ and the behaviour seems to be the same.

when a user tour points to a specific assignment, it does not work.

/mod/assign/view.php?id=960 does not work

However when a user tour points to a specific quiz, it does work and the tour appears normally

/mod/quiz/view.php?id=233

All settings on the tour setup are identical, and the user tour display is showing nothing but a centrally displayed block saying hello - no css targets, etc. - we've reset the "show to all users" setting multiple times and think we can rule that out.

We've also spotted user tours not working on a turnitin assignment, but can't test that on the demo site