I think the point was that your D: install directory overlaps with your data directory, which doesn’t seem like a great idea. Does it still revert to C: if you e.g. had InstallFolder set to D:\plex_install and LocalAppDataPath set to D:\plex_data.
1.32.4 also apparently shored up some security issues with the Windows installer (some more details here), so you could be running into some fallout from that as well. That could be a red herring if logs from back in March say it was installing to C: though.
