Problem when updating Manual Steps using the "Edit Issue" button

On Jira 6, when updating a step of a manual test using the "Edit Issue" button, if I click on the edit button of step 1, then, without pressing "Update", click on the edit button of step 2, the update button is shown, but the steps can't be edited. And if I press update, a message will alert that "No steps are defined".

On Jira 5, performing the same steps, all the steps can be updated but previously edited steps can't be edited again before pressing "Update"

Screenshot-1 belongs to Jira 6, Screenshot-2 belongs do Jira 5