I looked into this a few years ago, also with a simple Windows-shipped program.
IIRC Windows 10 just won’t do that. If you get same results, try asking Microsoft.
I forget if it worked any better if I turned off the UAC prompt, but that’s a bad idea.
I do this to a desktop shortcut all the time. It works fine, but needs a manual start:
A manual one-time plan is to install Duplicati as a Windows service as SYSTEM.
If you also want tray icon, use the --no-hosted-server option to use service’s.
