working in Odoo16 EE

i have installed Odoo's app Recruitment and want to customize through Settings -> Technical

i have added 2 Models, both contains "applicant_id" field as Many2one with reference to model hr_applicant

in hr_applicant model i have added 

1) x_hr_applicant_education_ids as One2many with reference to model x_hr_applicant_education

2) x_hr_applicant_experience_ids as One2many with reference to model x_hr_applicant_experience

when modified existing view through Settings -> bug icon -> Edit View - Form and added editable tree and run it is not editable, please check 3 screenshot below for reference.

please help what i have done wrong here, why it is not editable?

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regards