Logic Pro sessions corrupt and unusable!

I worked on a Logic session, saved and closed it. Now (for no reason that I can understand), the project file has ".logicx" at the end of the filename, while other projects simply say the project name. So all functioning projects are titled "Opening Scene" and now this troublesome filename is "Opening Scene.logicx" When I try to open it, I get the error message:

"The file couldn’t be opened because it isn’t in the correct format.

The file might be corrupted, truncated, or in an unexpected format."

When I right click and view package contents, it doesn't look the same as other project files. There is only an "Alternatives" folder, and its contents are essentially blank. When I "Get Info" for the problem session file, it says the file size is 0 KB. It's like the entire session vaporized. This has happened to several sessions of mine sporadically over the last 6 months, and as soon as I see the ".logicx" suffix pop up, I know the session is gone. I'm a working composer and this is my livelihood, and this is a scary enough problem that I may stop using Logic completely. It's been my go-to DAW for 20+ years, but I can't risk losing sessions for no reason. I can't find a solution. Desperately need to access this session. The first time it happened I spent hours on the phone with Apple, and the ended up telling me the only thing I could do was reinstall my operating system and start from scratch. If anyone has any ideas, I'm all ears! #sofrustrated