Hi there, @srikrishnafoods. Since the issue you are experiencing is unusual, I recommend that you contact our Live Support team. They can take a closer look at your account and help determine the cause of the issue.
To reach them, navigate to the Menu section > (?) Help > Help and Support > Contact Us. In the text box, provide a brief description of your concern and click Continue. After that, you can choose either Chat or Callback. Be sure to check their support hours for availability.
In the meantime, if you haven't done so already, you can continue managing your GST in your invoices through a web browser.
If you have any additional questions, please feel free to revisit this thread.