Sub agent is not getting commission on their customers orders

Sub agent is not getting commission on their customers orders (when these orders are placed by the customer himself)

Used the.demo link.

Steps:

Created a sub agent under demo agent with user id: sub1

Logged in using sub1 account

Used the affiliate registration link of sub1 to register cust1 customer account.

Logged in using customer cust1 account and placed an order.

Result:

Viewing Cust1: it has sub1 as it's sales agent.

Viewing Order details: agent account filed is empty and no commission (for sub1 nor for demo accounts were present)

If we use sub1 and place an order on behalf of Cust1, everything works correctly:

I..e Viewing Order details: agent account filed has sub1 and  commission for sub1 and for demo accounts are present)

Kindly advise.