Profile setups not checking Service request duplicates

Hello,

After enabling  profile options for checking duplicate service request, system not identifying duplicate service requests.

Below are the profile settings set in the system

Services: Check for Duplicate Service Requests: Yes

Services: Service Request Duplicate Criteria : Item Instance/ Customer, Item, Serial Number

Set the system profile Services: Check for Similar Service Requests : Yes

Service: Service Request Duplicate Timeframe UOM   : DAY

Service: Service Request Duplicate Timeframe :  30

Test case:

Create a SR for customer ABC for item LAPTOP,  SERIAL 123 AND INSTANCE 100. SR created in OPEN status.

I can create another SR for the above  customer ABC, item LAPTOP, SERIAL 123, INSTANCE 100 without any issues.