Dell Precision 5820 USB-C Ubuntu 18.04 install blank screen

Hello Team, 

This is the S/N -> (Service Tag Removed- TOS Violation) and we 're trying to install ubuntu 18.04 on this model after the install splash screen it goes to blank screen . we added below directives 

In the grub "Install Ubuntu" prompt.

( Press 'e' ) Remove "quiet splash"

Add "nomodeset acpi=off"

Then hit "Ctrl + x "

Still no luck. Please let me know how to proceed from here. We already tried keeping acpi / nomodeset alone. Still no luck

Ubuntu 20.04 LTS no issues, it loaded smoothly. 

In our environment, we having old versions of 5820 which worked before acpi/nomodeset 

Than

Jay