Update =Resolved- After completing troubleshooting, a DELL-Cares agent setup a x17 R1 motherboard replacement.
AW3821DW (the monitor), using its original DP to mDP cable (one of the several packaged with the monitor), connected to The Monitors Display Port (DP) and the other end connected to x17 R1 mini display port (#8) - is not working at all. x17 R1 does not even recognize that there's an extra monitor present. However, all other (non-Display Ports) work (max 120Hz).  These products are both basically designed alike. These should work together right out the box. They are not working. I have tried to get the 144Hz display setup working with both windows 10/11, tried all types and versions of HDMI, installed all drivers I could find (ALIENWARE_AW3821DW-MONITOR_A00-00_DRVR_V9YX1 - this driver install even found this monitor and correct port, but unable to install anything, dunno why), have tried all the combinations above with the dGPU enabled and disabled but none have worked so far. Help us Obi Wan - Your my only hope. The display port and 144Hz works perfectly on my other PC. Right from the get-go!
AW3821DW, x17 R1, mDP not working