Dell is now coming to replace part inside the laptop, I'll update you after they've fixed the defects. 
I just got this new laptop and disabled all non windows services rebooted and ran geekbench5.4.5. It got the lowest score of all results for 9520, not just by a little, but by a lot. ~25-30% lower on all tests. It's plugged in and located a large room with A/C. When I compare result details with other 9520's report details almost everything is identical, except I see their memory speed is reported at 2394mhz, while mine is reported at 967mhz. When I load up CPU-Z, and review the memory tab I can see the speed of the memory on my laptop changing all over the place. At times up to 2394mhz but mostly at 997mhz. I'm not sure if this is a simple fix such as an OS setting, BIOS setting, geekbench software issue. More concerning is if I have a hardware issue perhaps with the memory or controller? Any ideas what this could be? Troubleshooting steps to try? Thanks for any help. Results here -browser.geekbench.com/v5/cpu/15346443
Branch new XPS 15 9520 with very poor performance