Problem on Baseline date getting disapper during MIRO

Hello SAP Experts,

I am doing MIRO and while doing this I am inserting Baseline date under the "Payment" tab. and when I enter, the Baseline date I insert get disappear and so I am not able to post the Invoice and keep giving me error that "Specify Payment Period Baseline Date". I am specifying the Baseline date but I don;t know why it get disappear when i click enter or anywhere I click. Please check the screen shot I have attached.

Note: Payment term maintained in PO and Vendor master also that payment term select field NO default.