Connect Customer Order No to the New Case created using "My Call Center" for External Caller

I was trying to create a “Case” using My Call Center > New Case in IFS Cloud 26R1 environment. 

I observed a confusing behavior. I’ve added the test steps as below. 

Could you please look into them and let me know how can I solve this issue?

Functional Steps

I’ve used below steps to create a new case.

1. Go to New Case using My Call Center (Relationship Management > My Call Center > New Case) added a Customer.
2. For “Caller” section, “Caller Type” External is selected. External caller is selected from the LOV. 
3. Make the toggle “Connect Object” TRUE, selected the “Customer Order” as the object. 
4. I couldn’t enter the “Customer Order No”. The field “Customer Order” is not visible. 

 After, I’ve done below steps. 

5. Changed the “Caller Type” to “Internal”. 
6. Selected the Customer Order as the object. Then “Customer Order” field is visible.
7. Customer Order No is selected. At this point, the value in the “Caller” is not removed (refer below figure).

8. After I changed the “Caller Type” value to “External”. Then, the selected Customer Order No is not removed. 

8. Created the Case with this. Case is created with the entered Customer Order No connected (refer below figure).

This seems, “My Call Center” > New Case is having an issue. 

Is anyone experienced this before?

Could you please help me how can I solve this issue?