I thought I let you know my experience with that issue.
I am using a HM90 and had several challenges.
1) Installer freezes if mouse is attached
If any mouse is attached to the device (tried it with two different mice), after several seconds of showing the graphical installer, everything freezes. This can happen on the first page of the installer - before clicking the first time on next. No input by the mouse or the keyboard is recognized.
I had to reboot the HW using the power-button. After unplugging the mouse, this did not happen anymore and I could navigate through the installer.
=> Don't have a mouse attached during Proxmox-installation
2) Installer freezes at "Creating LVs"
After some research, I have the impression this seems to be a common issue. Often people are just told to "wait up to 20min". As the installer didn't seem to continue for several minutes (at 3%), I did some other stuff. After maybe 30min, I realized that the server rebooted, because it was showing the boot-menu of Proxmox. I started the installation again and now the Creating of LVs was done in a matter of seconds.
=> Wait if it hangs at 3% (some report it might take hours) and after some time it will continue / the second try will be much faster.