A business rule isn't triggering the expected text value for a field.
Reproducing the Issue
You have a business rule that sets
Field A[country] equal to [TEXT] UK
You expect this rule to trigger however the field remains blank.
Field A has a picklist associated and the text the business rule is inserting [UK] is not part of the list of the picklist values.
The text triggered by the rule must always be part of the value list from the picklist associated to a field.
Please select the correct value from the picklist, in this case GBR
So edit the rule to the following:
Field A[country] equal to [TEXT] GBR
Now trigger the rule; it should maintain the correct value for this field.
KBA , LOD-SF-EC-JOB-RUL , Job Info Business Rules , Problem