That's a bug in the program, as this form is not required if you don't have passive activity losses. It is generated by the software but it should not be needed. Deleting the form doesn't help, it comes back immediately.
From CA FTB 2021 Form 3801 Instructions:
"Who Must File: Form FTB 3801 is filed by individuals, estates, trusts, and S corporations that have losses (including prior year unallowed losses) from passive activities."
