While using the Allow Tax Overrides option, tax will only calculate once, and then is stuck on that number, never changing.
AvaTax for Salesforce
- Uncheck the tax override option and calculations will resume.
This is expected behavior for the tax override setting. Once there is a value in the tax field (for any given product line), the tax amount will always be forced after that. The override setting is intended strictly as a temporary measure to be used rarely.