I have same issue since 3 days. -purchase completed, invoice appears in my.presonus/orders. But no registered product under my.presonus/products. No confirmation email and no product key.
I already opened a ticket, got the same reply as fatbob1. But the suggested procedure within S4 does not work (you need a key for the upgrade, registered on my.presonus)
Now, the local support is going to forward the issue to the central Support in the US. But I won‘t get an answer before Monday (... Thanks Giving).
I try to be patient...