Lightroom 12.1 Not Responding on Startup

I have a new Dell 5820 Workstation, 32 Gb RAM, NVIDIA RTX A2200 video card (2 GPUs). 

Lightroom will start, but if I attempt to access any menus, hangs and shows Not Responding in the top title bar.  It is particularly onerous when attempting to import files.  Any mouse actions cause the screen to go milky wight, and the Windows Program Not Responding dialogue box appears.

I have uninstalled problematic applications, turned off GPU access and started the program as Administrator.  Once the program closes for not responding, the: Process shows as active in Task Manager, with 0% CPU, 15.9 Mb RAM