Tax_date is not changing when Schedule Ship Date changes

We are on Oracle EBS 12.1.3

When the order is created, tax_date is defaulting to 31-DEC-40 23:59:00 it is because schedule ship date defaults to 31-DEC-40 23:59:00 when the sales order line is saved. This tax_date causing the tax to be calculated on the order even though customer is on exempt until 2026.

Later when the schedule ship date is changed to 2023, tax_date is not changing, so tax is not recalculated to reflect the tax based on exemption which is valid until 2026. The expectation was that zero tax on the order because customer is tax exempt until 2026.

As a work around if I change the promised date and request date then tax date is changing and making the tax re-calculated to zero.