I have exactly the same problem. The project is downloaded from the cloud without problems and loaded into the desktop application (latest version from the official site 2023.09 build 075, 64bit). All tracks in .flac format when converted to .WAV are empty, it only works if you download the project combined into one track. I tried it on 2 different computers with Windows 10 and it doesn't work. I think that the problem is in the program; it does not convert files correctly.