Migrating from Apple Photos - 120gb missing?

hi everyone,

I decided to recently migrate from Apple Photos to Lightroom CC yesterday, selecting the "Migrate From Apple Photos Library" option.

My Apple Photos library is 265GB. I didn't have an option to do this migration locally, so have started the process for the cloud storage after upgrading my Adobe plan.

It's doing the migration now, and gave me a report saying: Size of Valid Assets : 140746347025 (140GB).

What happened to my other 125 GB???  I think that means almost 1/2 of my media is not getting transferred? Can someone help me understand this, and if there's a way to determine what was not transferred?

After the migration is complete, are the images removed automatically from Apple Photos? If yes, maybe it'd be easy to see what wasn't copied... otherwise, I have no idea how I'd know.