Can't do a Debug build

Not sure where this is coming from, and in fact, it might not be VB, though VB is what I'm working in...in case this has anything language dependent about it.

I have a project that builds either debug or release, but always puts the output into the bin/Release folder. I built it this morning, and noted the time of the file in the release folder. It matched the build time. I just rebuilt and noted that the time on the file in the release folder is now the current time. The debug folder exists, but it is empty.

In project properties, on the Compile tab, there is a Build output path. That is showing bin\Debug\ when in the debug configuration.

After a bit more testing, I have found that other projects are doing what I expect. If I Rebuild Solution, then if I am in the Debug configuration the project is compiled to the Debug folder, and if I am in the Release configuration, the project is compiled to the Release folder. For this one project, whether I am in Release or Debug configuration, the output goes to the Release folder.

I then ran a second test, and VS2019 is doing the same thing. Somewhere in the project, despite showing that Debug builds to the Debug folder, it is building to the Release folder.

Any idea where that might be?

A couple other points: I deleted the obj and bin folders. In obj, only Release was recreated. In bin, at first it was only Release, then Debug showed up...eventually, probably after me fiddling with building and rebuilding one or the other. The Debug folder has never gotten anything placed there, but at least it exists.

Checked the vbproj file, and everything in there appears correct. I can see the output paths are correct for debug and release.

Yeah, I was going to suggest textual examination of the project files. Aside from the paths being correct, does it correctly note whether the project is in debug build mode?

It certainly seems to be working in every other way.