Why are there no invoices on a Cash P&L?
Cash P&L is all about cash - what has actually happened, not what is likely to happen.
The focus of the Cash P&L is receipts not invoices. For this reason you will not see any invoices on a Cash P&L.
A simple way to understand the Cash P&L is that if an entry appears on your bank statement (and it has been added into SILQ) then it will be on the Cash P&L.
The Accrual P&L on the other hand will have all of the invoices as that is looking to what you have invoiced as opposed to what you have actually received.