Why for Sales in USD, the allocation journal doesn't take entire source amount to allocate?

Requirement:

Create a allocation rule, where the source amount should allocate to the target account based on the Sales data defined as Basis. but need to exclude 5 locations from both sales calculation and allocation journal.

Issue:

1.  If we exclude 5 locations in exclude section, then the entire source amount is not picking up. (Ex: If source is 60000, it is picking 58000 coz it's still including locations sales for allocating.
2. Then the amount allocating to target accounts is also not as expected.

What can be the solution to exclude 5 locations and still it should draw entire source amount and allocate the amount to target as per sales defined as Basis?