Only SOME save data gone?!

[AortaPlatinum]

I'd be less angry and confused if ALL my data was gone, but only some is.
No I'm not stupid enough to not understand the auto save mechanic, here's what happened. A few months ago I wanted to see if moving the game from my HDD to my SSD would improve pop-in, so I moved it all over using Steam's own "move install folder" in the game's properties. I then uninstalled the game to make way for the ♥♥♥♥ off gigantic and very boring Starfield. After playing for 30 minutes and hating it I then re-installed Frontiers to it's original spot on my HDD.
I went to boot it today to play around in the Cyber Space stages and my last save is from LAUNCH DAY.
But the weird thing is, SOME of my save data was retained. I still have the 100% bonus costume- the crown- and checking my game saves in my appdata folder shows my save data for arcade mode and battle mode were last updated when I actually played them. But my main saves are just... gone. WTF.

[Khanwolf]

Did you search the Steam Cloud and your Profile Folders? Steam does Backups with the right Settings!

You can access your Cloud with a Browser and download Files individually with the RemoteStorageApp on the Steam Official.

https://store.steampowered.com/account/remotestorage

[AortaPlatinum]

I checked, but for some reason it's the same deal there- recent arcade, battle, and even settings data, but only an auto save and a manual save from Nov 22. Which is especially weird because I had all four slots filled out with save data, one for my 100% file, one at the start of Rhea because it's fun to speedrun like a stage, and one that was a lvl1 playthrough where I didn't upgrade anything- but Steam cloud stopped backing up my saves the very first time I got to Chaos Island.
It's a damn good thing I like this game lol, guess I'll just finish it again

[Ashley the Pikachu]

This happened to me too, I was even extra careful to copy the appdata so I'm at a loss. At least I don't have to fully start over.

My save might have been from Nov too which is odd but I can't recall for sure.

[Mez Koo]

Have you used Hedgemod Manager?