This question is a bit old, but wonder if you figured this out?
I’m note sure if this will be helpful, but hope one of these two will help you or others.
In the past, I worked on a number of Proliant DL servers and had to install drivers with some minimal OSes. RAID controllers in particular seemed to have issues with RHEL/CentOS installs (what I usually installed at the time). IIRC, drives would be seen but the RAID controller was an issue. I had to provide drivers from the below HPE link to get successful installs.
Oddly, I had issues installing over USB 3.0, but no issues with USB 2.0 iso installs of Ubuntu.
HPE Drivers https://support.hpe.com/hpesc/public/docDisplay?docLocale=en_US&docId=c05029574