Create an assignment. In the "Submission settings" section you can choose an option für "Attempts reopened" regardless of the choice in "Require students click submit button".
This behaviour is majorly misleading: It gives trainers the impression that they can choose a setting that is preventing students from changing their submission. Actually though, the setting has no effect when "Require students click submit button" is set to "No". So this option should be grayed out in that case.
Edited to add an update:
From the comments in this issue, it is clear that the option "Attempts reopened" is misleading, and the setting name and help text should be amended to better explain the functionality.