Sub report works correctly but once sub report connect to the main report it doesn't show any values

In AR Register Detailed report, my client has report fully modified according to their requirements. in their report they calculate total amount based on CuryOrigDocAmt field in ARInvoice table. when calculate total they add 10% vat to the total. They request to modify it when customer is non taxable , the 10% vat must not add to the total. only taxable customers should billed 10% vat. 

In their AR Register detailed report, I tried to do the mentioned modification. I consider the ARInvoice.CuryTaxTotal field to identify weather customer is taxable or non-taxable. But with existing relations on their AR Register Detailed report , it doesn’t retrieve data of ARInvoice.CuryTaxTotal field. Beacuse of that i implement two sub reports get values to the main report.

The question is two sub reports retrieve data successfully. when i connect it to the main report the main report not display any values. 

Here i attached two sub reports and main report