Role Issue in OneSpan

I have got into a very weird scenario today. Using Apex SDK to create package in OneSpan.

I have created a package in OS with placeholder1 assume roleId as 'ph01' and signer1 with roleid as 'signer01' 

Now when I create a transaction and set a sender manually ([email protected]) (email address isn't part of any of the signer), the placeholder role is being replaced by sender instead of actual recipient. Ideally sender should be an seprate entry, however it replaces the placeholder. 

In the logs, I have found out sender and signer1 has the same roleId which is "signer01", I just want to understand how this is possible that two role with same Id exists with different signer