Reset Cart After Redirection

Enable the following option from the settings menu of the shopping cart plugin and you will be good:

Reset Cart After Redirection to Return Page

Yes, thank you: I already had the option activated, of course, but eventually I solved the trouble.
One must redirect to a precise page, let’s say something like https://www.mysite.com/whatever/page_success.php. I used a generic return, like https://www.mysite.com and this is not working.
Thank you anyway.