Tax zone configuration not working as expected

Hello we are trying to define Northern Ireland as a new tax zone and define a tax rule so that whenever the ship to location has the Northern Ireland address the rate picked should be for example GB reduced or else it should be GB standard.

We have defined a new tax zone and created a tax rule stating user defined input as the tax zone created , but unfortunately the rule is not being triggered even if the conditions are met , in simulation (x) is mentioned against the tax rule , thus it is not working as expected.

We have tried created a new tax jurisdiction as explained in the link shared below but not working as expected. Requesting guidance if anyone has worked on the tax zone and tax rules derivation on the basis of the zones configured .