Insert data through a reference that contains "Is a part of?"

[OsArcos]

Good afternoon, I created an invoice insertion table, which when the form is saved through LINKTOAFORM, automatically opens another form to insert the amount paid for a particular invoice. this part is working fine.

But I created another table where the calculation of the day is done, it happens that many times there are small invoices that are paid directly from the cashier, for that I inserted a reference with "Is a part of?", where I can insert the various invoices that are paid daily through the cashier

But when I insert the invoices through this reference, and when I save the invoice form, the payment form does not open. in fact I didn't even need it to open the payment form, because as the payment was made through the cashier, it's a payment in full, I just needed the record to stay as payment, but inserting it through this reference I'm not getting any of the situations works, that is, I save the day's calculation form, the invoices are inserted into the invoice table, but I can't get the data to enter the payment table.
If anyone can help me I would be grateful. Thanks

[SkrOYC]

I don't think this setup is right since the payment shouldn't be parent of the invoices, it's usually the opposite

References between tables - AppSheet Help