Thank you for reaching out on this.
Can you please check in the tax settings for the Lodging frequency for both GST and PAYG Withholding?
Make sure both frequency is reflect the lodging frequency of your client's.
Please let us know if you are able to see the desired IAS come up for preparation.
Thank you for the additional information Julieanne,
So we can better assist you on this, can you please reach out to our support team via Contact Us?
Our support team would be able to help resolve this after verifying a few things with you on your client's file.