I have been in contact with Occulus through the support tickets, but it has went dead air.
So I am having trouble with downloading the Rocket League DLC. It is the only DLC I have purchased. At some point Beat Saber attempted to updated and failed and after that I have been unable to download the DLC. When the the Beat Saber update fails, I have to uninstall and reinstall Beat Saber to get it to run again. Then after that the DLC will not download. All the free DLC songs download. Just not the one I have paid for. I see this is a problem other people have had. It is mentioned a few times in the reviews of the game on Occulus's own platform.