appdynamics: how can I exclude an exception from being counted in the "Errors per minute" metric in health rules?

Question

I tried to achieve that by configuring the exception as ignored in Configuration -> Instrumentation -> Error Detection, under the section "Define exceptions or log messages to ignore when detecting error Transactions", but that did not work. Why? According to the documentation,

AppDynamics still detects the exception, logs the exception, increments the exception count

, BUT

AppDynamics does not count the business transaction in which the exception occurred as an error transaction

. So what am I missing? Doesn't the "Errors" word in "Errors per minute" metric mean the above "error transactions"? From what I see happening, it behaves as "Errors" word in "Errors per minute" are really exceptions and not "error transactions". So my question is: how can I exclude an exception from being counted in the "Errors per minute" metric in health rules (Alert & Respond -> Health Rules)?