So, basically you have set up two different leave types: some require approval and some do not. Now, if you create a leave request that requires approval, it needs to get status APPROVED before it gets posted to the infotype. Now, if you want to remove/delete a leave that required approval, also the deletion requires an approval. (Maybe the manager does not agree with the change of holiday plans that he already approved etc.). Now, when you delete the leave, it gets status SENT (and is sent to the manager, right?). Actually it is not the leave the is in status SENT, but it is actually a "request for deletion". After approval the leave gets deleted.
If you want to change this, you might need to do some additional development. Basically you could set the status automatically to APPROVED as a separate step in your workflow. Of course you need to check that you are doing it for the "deletion request" (operation is 'DEL'). The approval can be done with method CL_PT_REQ_WF_ATTRIBS->APPROVE. Or if this method does not work, you can at least see how a status of leave request can be changed with code.
Regards,
Karri