Pay Later for 20B - Functionlity not applicable for zero fee forms

I filed Form 20B yesterday and used Pay Later option.

It generated "Pay later" challan with SRN number. Expiry date is 5 February

I also got SMS saying 20B uploaded and payment status is "NOT PAID"

Now I am trying to pay for it using "Services-Pay Fees-Pay later" option.

Then I provide SRN number but it gives this following message:

"Functionality not applicable for zero fee forms"

But my form is not zero fee form - Payment to be made is clearly mentioned in pay later challan.

So anyone has any idea what is wrong?

Is anyone else facing same problem?

Thank you