Screen_off after ACPI: bus type drm_connector registered

[winzawoo99]

I m trying install Proxmox on dell poweredge R320 server.
My monitor off while installing, after acpi: bus type drm_connector registered.
My Bios, 2.90 LifecycleController and iDRAC are 2.65.65.65
I would like to request any suggestion to fix this issue.
Thanks advanced.