If the update of an existing issue has not been successful, the edit screen reloads and the first input field gets the focus, not the one (if there is more than one error, the first one in screen order) which caused the update to fail. This can really confuse the user when the issue has many custom fields and one of the last fields in the screen order cannot be updated (e.g. because it has a string in a number field). They need to see the error (or even a text that there is an error) right after the update failed.