Weird confirmation window after saving a form

[zavzi]

Hello everybody

I have a small app where users can record their activity.
Something is troubling them.
After hitting save, a confirmation window appears which does not make sense:

Confirm
Are you sure ? No - Delete

Even if I missed something with actions/workflow/rights/etc, can somebody explain what is the meaning of this ?
How do I modify it / get rid of it ?

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