I have found an issue with our user tour on the find courses page of our LMS. I assume that this issue would affect any user tour on any page. I am using Totara 11.6 with Chrome Version 75.0.3770.80 (Official Build) (64-bit). The steps to recreate the issue are as follows. 

1. Log in to a regular learner account

2. Go to the Find Courses page

3. Click “Reset user tour on this page” in the footer

4. Without closing the tour, click the refresh button in the browser

5. When the user tour appears again, close the tour with the “x” in the top right corner of the dialog box

6. Click on any course

7. Click the browser back button

After the find courses page is refreshed again the issue is resolved. The issue does not occur in Internet Explorer.

Our Totara partner has indicated that modifying the core would be required to resolve this issue, so we have decided to report it and wait for a patch or the next version update. Let me know if more information is required.