VS 2019 remote debugging can't "see" my symbols (C++)

Sorry if this is a duplicate -- I've looked at this and this and others, but I can't find my problem.

A program I build debugs successfully on my local machine, but when I try to debug it remotely, I can't set breakpoints in my code. I've opened the modules window in the debugger, and under Symbol Status for my executable, it tells me "Cannot find or open the PDB file." I try to load it manually, and get the error, "A matching symbol file was not found in this folder."

I created a minimal (hello world) app, and I can debug that, so I'm able to reach the remote PC. Indeed, the app does start up and run on the remote system. So, it isn't an access issue.

Not sure what else to say about this, other than to show you my project debugging configuration:

Any ideas are MOST welcome. Thanks...