Error with a link in task notification

Hi,
we have a problem when the user clicks on the link in the activity notification. When the user clicks on this link it is mistakenly sent to the homepage and not to the trip activity.
What could be the problem?
I attach a path:

1.I access the notification

2. I click on the notification that should take me to the journey task

3. once I click it takes me back to the home page

Thanks
Best Regards
Gianfranco