Hello,
I think to have the same problem with the same version of server: only software is registered into db, all the other informations are registered into db as empty lines.
For example, in the disk section of hardware, i can see three line for three drive, but all columns are empty.
I have installed ocsinventory-server with setup.sh on Ubuntu 20.04 and download the sources of it (and ocsreports) from github.