Control when required field through page composer pops up

Summary:

I have made the field Product Fiscal Classification (PFC) on the invoice line required through page composer, specifically for unmatched invoices that are manually created or created through IDR.

Below is the expression I have used.

#{bindings.PoHeaderId1.inputValue== null && bindings.InvoiceTypeLookupCode.attributeValue!='PAYMENTREQUEST' && (bindings.Source.inputValue == 'Manual Invoice Entry' ||bindings.Source.inputValue == 'IMAGE')}

It does work, but the required field pops up immediately when you click into the invoice lines area, before even entering amount. How can I control when the pop up occurs?

I have tried various things like also making line amount required in the expression, but when I do this, the required pop-up no longer appears at all.