Sales order lines search filter "Primary Salesperson" showing No matches found

Summary:

We have enabled the sales order line search filters all working fine expect "Primary Salesperson" when try to search the data with this filter showing "No matches found" after further investigation found the in lines primary sales person field is showing blank in sales order lines.

But sales order is searched in manage order page it's showing in header and lines the sales person name.

What is the reason the data is not showing in search filter is there any configuration setup we missed?

Version (include the version you are using, if applicable):

25C

Code Snippet (add any code snippets that support your topic, if applicable):