OBJ too small on MacOS Sequoia

Pretty much what the thing says. If I run Substance Painter in Windows 11, It loads the OBJ file with no issue. But if I use the exact same OBJ file on my MacBook Pro, running Sequoia and the literally most recent version of SP (installed today, in fact), it fails out, telling me that the OBJ file is too small.

Why would the two versions deal with the file differently? I am using the exact same process to load it on the Mac as I do on Windows, so I would think it should also load. (New file, choose template and then the file, make sure I'm telling it OpenGL instead of DirectX - all the stuff that loads it successfully on Windows.)

(I'm having a different issue with working on the Windows version, hence trying to get it working on the Mac.)

Any ideas why the files loads in Windows but not on the Macintosh?