TG16CD Saved games missing

I found a strange repeatable bug.
Found in Ys games. Easiest one to replicate it in is YSIV english translate.
Libretro/retroarch: all latest cores etc. Nothing beta.
System: Win10pro 64bit, latest updates
Only weird things about this system: it has a projector instead of screen. my roms are on a "storage pool", which I think is RAID5?

To replicate:
Play the game for a bit. Save it a few times in different slots.
Exit the game/libretro.
Load the game back up, you will see your saved games.
Play the game more. Save in some other slots or over your current slots.
Turn your monitor off. and/or let the computer go to sleep (I did not do the later). However, the platter hard drive (non SSD) did sit long enough to stop spinning?
Come back to your game, it will be frozen.
You will be forced to stop the application.
After you load it back up, your original saved games will be there. But your new saved games won't be.

I'm wondering if they don't immediately get saved to disk and were still memory resident only?

No file or test is named. Start by tracing libretro-common's save-game persistence path and reproduce the reported sequence with the Ys IV translation, including the forced stop after the system or disk becomes idle. Done means newly created saves remain available after restarting the application.