When entered a new user/password combination on a known website, Enpass asks you to either "Create a new entry" or "Update an existing entry". When selecting "Update an existing entry", selecting the entry you want to update, and then clicking "Update", Enpass does not update the password in the selected entry! This is especially bad when assigning new passwords because they will they lost after the 30 second clipboard clearing delay.
This happens in Enpass Portable 5.6.5 on Windows 7
Also: Help > Contribute > Report a bug doesn't seem to do anything