Update index.md - identifier breakdown

Author: samkcrespo

src/engage/audiences/index.md

@@ -261,7 +261,7 @@ Note the following limits for the CSV downloader:
 
 ## Identifier Breakdown
 
-The audience summary is a breakdown of the percentages of external_ids of users in the audience. These are the default IDs that Segment includes in the Identity resolution configuration. Segment displays the percentage of the audience with each identifier, which you can use to verify the audience size and profiles are correct.
+The audience summary is a breakdown of the percentages of external_ids of users in the audience. These are the default IDs that Segment includes in the Identity resolution configuration. Segment displays the percentage of the audience with each identifier, which you can use to verify the audience size and profiles are correct. It's important to note that the update of identifier breakdowns on profiles does not occur in real-time.
 
 > info ""
 > The Identifier Breakdown won't show custom IDs included in the Identity resolution configuration. Segment only displays external IDs in the breakdown.