images and video not saved

Over past 2 days, I took some photos and videos with One X, but none of them saved (no new files show up on SD card). The last time I used it/it worked was Nov 28, 2020 (this is the date of the most recent saved files). I updated firmware and software today, and it started saving again. Can any of the "missing" files (from last 2 days) be recovered, or was there nothing written to the card to be recovered?

I'm on a Windows 10 computer.