[2021] On first run after re-install, program hangs spinning on logo screen

I got this through Epic; played for awhile (1d 14h per Epic's data), then uninstalled it.
This was a few months back.

Now I went back and re-installed it, ran first time and Ubisoft downloaded a large update to the game, then displayed "Play",
but when I click Play, it opens the AC:V logo screen, initializes, then just sits there with a spinning circle, essentially forever (actually, I only left it spinning for 20 minutes, but that should be sufficient).

I tried the following fixes with no effect:

1. put Ubisoft offline
2. ran Verify Files; all verified fine.

Is there a fix for this??

My system:
Windows 10 Pro 64-bit, all drivers/files updated
NVidia GTX 1070 Ti, current drivers
CPU: Ryzen 7 3700X
Install disk: Samsung 980 Pro, PCIe4 NVMe interface, plenty of free disk available
32GB DRAM, 18GB free