Tax status rule for Intercompany transactions doesn't work for all countries

Summary:

For Canada, we have a Tax Status Rule setup for intercompany transactions to result in an Out of Scope rate. This rule gets applied to the intercompany invoice and an Out of Scope rate appears on the invoice. Similar tax status rules are setup for Ireland and United Kingdom. However, when Intercompany invoices are created for the same supplier as the Canada invoice, the Ireland and U.K. invoices do not get an Out of Scope rate on them. What could be causing the different behavior?

I've reviewed the tax setup for all three countries and don't see any differences that could cause the different result. The same supplier is used for all 3 intercompany invoices so the supplier setup isn't the issue. I tried to review the invoices in the "Manage Simulator Transactions" but that didn't show me anything.