Running setup-x86_64.exe from cmd does nothing but works from cygwin itself

[wsnyder@wsnyder.org]

I have a Windows Version 10.0.19044 Build 19044 system with Cygwin installed a while ago.

Opening the cygwin terminal (which works fine), I see it is running:

CYGWIN_NT-10.0-19044 version 3.3.6-341.x86_64 (corinna@calimero) (gcc version 11.2.0 20210728 (Fedora Cygwin 11.2.0-2) (GCC) ) 2022-09-05 11:15 UTC

I needed to install some packages so downloaded setup-x86_64.exe onto my desktop. When I run it from the desktop I get the "busy" cursor for a fraction of a second and nothing happens.  When I open the native Windows cmd prompt as administrator, and run "setup-x86_64.exe" or "setup-x86_64.exe -v" or "setup-x86_64.exe --asdjasdjaskdhj", I just get the prompt back.

If, however I startup the cygwin terminal (vs cmd window) and run setup-x86_64.exe, it starts correctly.  However I'm afraid to run it this way as if it crashes I'll presumably never be able to run setup again.

This is a work machine so while I have admin, it's completely possible they've added some broken virus checker rule that is now preventing it from running. But, I get no alert, which I normally would doing something unusual, and that it works under cygwin itself seems odd.

Please advise, thanks