Example:
Searching for the user that contains the following string: mac.local.nobody
If you select CONTAINS and then enter "mac.local.nobody" (no quotes) you receive results
If you select CONTAINS and then enter "MAC.local.nobody " you receive ZERO results.
If you select CONTAINS and then enter "mac.LOCAL.nobody " you receive ZERO results.
If you select CONTAINS and then enter "Mac.local.nobody " you receive ZERO results.
etc, etc
Appears that there are MANY functions in the new UI that Enforce STRICT case sensitivity where its not logical to assume to enforce this strictness.