Hi
I am also having this issue and your explanation doesn't quiet give enough clarity
please i would really appreciate if you could help out

Hi,

The schedule_pay actually referenced with the salary struture_id in the hr. contract module and the payroll module used the compute function to add the schedule_pay field

schedule_pay = fields.Selection(related='structure_type_id.default_struct_id.schedule_pay', depends=())

many2one field for linking the hr. contract module

Hope it helps