I've found an issue with the chat module. Updating the Repeat/publish session times setting doesn't actually update when the changes are saved.

Steps to replicate:

1. Create a chat activity
2. Set Repeat/publish session times to 'At the same time every day'
3. Save and display changes
4. Go back to the settings of the module
5. Change the Repeat/publish session times settting to 'At the same time every week'
6. Save and display changes

Observed: The date/time of the next session and time remaining until next session does not update

Expected: The date/time of the next session and the time remaining until the next session should be updated.

This also affects 4.0.4, 4.0.5 and 3.11.9