How to restore lost Photos from iCloud backup on MacBook Air

I have two devices, my iPhone and MacBook Air. All the photos from my iPhone are backed up on the iCloud.

My MacBook had a set of photos (around 70 of them) exclusively on the MacBook, i.e, not on the iCloud and ONLY on the MacBook. Initially, iCloud Photos sync was turned off on the MacBook Air.

Now I turned on the iCloud Photos sync on the MacBook but somehow those exclusive to MacBook photos kept showing up in the "Unable to Upload" section of the photos library on the MacBook. My iCloud+ account has sufficient space (over 100 GBs) so I know for a fact this isn't a space issue.

So I turned off the sync from the MacBook and turned it on again and now I'm unable to see those MacBook exclusive 70 photos anywhere! They're not there on the iCloud or on my MacBook. I can't see them in the Recently Deleted folder in iCloud or the MacBook.

This is pretty frustrating. I feel like they've been deleted somehow when I turned the sync on and off.

Can anybody confirm or tell me if I can find those photos anywhere?

[Re-Titled by Moderator]