Steps to reproduce the bug
Navigate to Default booking form
select a field so properties shown in right hand column
click delete field
*without* clicking save & close click on dashboard link on left
dashboard now shown
now navigate back to default booking form
the system shows the form without the deleted field, as I did not click save it should show the field

As I did not click save it should not have saved the changes
I can stop and restart the web server and the changes are still there

It would be good to have a button to cancel or undo button on the edit screen otherwise there is no way to reverse an editing mistake, unless I have missed a button / process that is documented somewhere