Final Fantasy IV save file disappeared randomly

[IRL Random Hajile]

Hello there! First time I've posted here in the FXPAK PRO section, but hopefully I can get some answers.
So basically, I received an FXPAK PRO last month as it was actually meant as a surprise birthday present for my little brother, who loved playing Super Nintendo. (He really loved the gift and was blown away by it)
It was working really well with no issues up until something weird happened... so my little brother was getting really invested in Final Fantasy IV (I think around 20+ hours), and saved his game. He waited a bit to make sure that the saving process went through, then he turned the console off afterwards. Upon loading his game the next time, his FF4 save data got wiped clean as if he never played the game before. That bummed him out when that happened, and I unfortunately was not able to back up the save data in time as the flashcart (and Micro SD card) was not in my possession at that time.
At first, I had the suspicion that maybe the CR2032 battery might have dried up, but here is the weird part... all his other saves for other SNES games like Super Mario RPG, Super Mario World, Kirby Super Star, etc. remain intact.
It was only Final Fantasy IV that was affected by this weird occurence.
The FXPAK PRO was played on my Super Famicom that I gave to him (capacitors were recently recapped and console was cleaned too).
If it helps, I shall also mention that I do have the v1.10.3-frs-v12 firmware (SGB support with Save States) set up for my lil bro there. Wonder if maybe the firmware that's currently being used at the moment might have something to do with this...? I've heard about BS-X games not working properly on this firmware, but are there other notable issues that are known about, and if so... should I just stick with the official v1.10.3 firmware for the time being even though it has less features at the moment?
Would like to know your thoughts on this. Thank you for taking the time to read.

[nuu]

This has never happened for me on my SD2SNES, but yes probably a bug with the firmware or your brother just had very bad luck. Corruption can always happen with electronics, that's why making backups is important. I know how he feels loosing 20+ or even 50+ hours of playtime in an RPG.
Unlike Everdrives, the FXPAK updates the SD card periodically when playing (the battery is basically only for the RTC I think), so I guess if you turn it off just when it's busy writing to the SD card it could corrupt. But that also sounds like very bad design to me, probably it writes to a backup file first and updates the real file at reset? I don't really know. If you are paranoid you might want to reset back to the firmware menu (hold reset about 2 sec) before turning it off like what must be done with MSU-1 games to keep the save.

I don't find it weird that your other save files are intact. If they were, the SD card or its filesystem might had been damaged.

I haven't heard of any save bugs with the unofficial firmware as I'm on v1.10.3 myself (I don't need save states and I have a real SGB2). If you don't need those features I recommend the official firmware, as it's known to be stable, we've been using it for 2 years now. Turn off things like in-game hooks if you are not using them as they can cause all kinds of problems. Even the region auto-patcher can cause problems in some games so I have it off as well unless I need it.

[IRL Random Hajile]

This has never happened for me on my SD2SNES, but yes probably a bug with the firmware or your brother just had very bad luck. Corruption can always happen with electronics, that's why making backups is important. I know how he feels loosing 20+ or even 50+ hours of playtime in an RPG.
Unlike Everdrives, the FXPAK updates the SD card periodically when playing (the battery is basically only for the RTC I think), so I guess if you turn it off just when it's busy writing to the SD card it could corrupt. But that also sounds like very bad design to me, probably it writes to a backup file first and updates the real file at reset? I don't really know. If you are paranoid you might want to reset back to the firmware menu (hold reset about 2 sec) before turning it off like what must be done with MSU-1 games to keep the save.

I don't find it weird that your other save files are intact. If they were, the SD card or its filesystem might had been damaged.

I haven't heard of any save bugs with the unofficial firmware as I'm on v1.10.3 myself (I don't need save states and I have a real SGB2). If you don't need those features I recommend the official firmware, as it's known to be stable, we've been using it for 2 years now. Turn off things like in-game hooks if you are not using them as they can cause all kinds of problems. Even the region auto-patcher can cause problems in some games so I have it off as well unless I need it.

Thank you for your response, nuu! I've decided to switch back to the official v1.10.3 firmware for the time being until a new official update from ikari_01 surfaces which will include SGB support, save states, and such. I originally went with the unofficial firmware at the time mainly because of the SGB support (though the save state thing is a neat feature albeit glitchy), and some games I imagine would benefit from the use of a save state feature like Jurassic Park on SNES for example which had no method of saving whatsoever... not even a password system which is quite ludicrous.
Mmm, I've also made sure that ingame hooks are completely disabled because of weird problems that could occur in games with it enabled. Though I do keep the Auto Region patcher on because my bro and I like being able to play the PAL SNES exclusives from time to time. So yeah, I'll bug my brother at least once a week to back up the save data since he started a new game in Final Fantasy 4, and he's made it around the halfway point. Also told him to hold the Reset button for about a few seconds once he's done playing to ensure the save is kept.

[nuu]

Just so there are no misunderstandings: holding reset a few seconds is to go back to the menu, so wait until you see the menu screen before turning power off if you do this. It's unrelated to the hold-reset-while-turning-off thing on the NES.