Photogrammetry Console App - Errors on PhotogrammetrySession/Argument Parser

This may be something quite obvious I'm doing wrong, since I'm a Windows programmer somewhat new to iOS/MacOS.

I downloaded the sample app associated with the Create 3D Models with Object Capture earlier this week and have used it over the week in multiple sessions successfully in Xcode 12.5 beta, no problem at all. This morning I opened the app and am suddenly getting errors that PhotogrammetrySession doesn't exist. When I do a Clean Build folder those errors disappear, but a new one "No such module 'ArgumentParser'" starts showing up.

I closed, quit Xcode, reopened, still the error. I removed the ArgumentParser package dependency, and then reinstalled. The error disappeared, but then the original PhotogrammetrySession errors reappeared. I cleaned build folder, and the PhotogrammetrySession errors disappeared, but the Argument Parser error reappears. I went through this cycle 2 or 3 times.

I deleted all of the files, downloaded the sample code once again from Developer.Apple.com, and the same thing happens again; on opening the file in Xcode Beta 12.5 the PhotogrammetrySession errors appear in the newly downloaded sample code. I can get rid of the Photogrammetry errors, or the ArgumentParser errors, but can't get rid of both. Is anyone experiencing something similar, or is this an obvious issue on my local machine that I'm missing? (Mac mini M1 2020, running MacOS 12 beta)

Thanks!