Cowon iAudio X5:Problems with 32 GB CF Cards and Original Firmware

[Festivus]

I've got two functional Cowon iAudio X5s. One is running off of a 256 GB CF card with Rockbox and the original firmware in dual boot. Now I'm trying to replace the 30GB HDD in the other one with a CF card. Given that I've successfully dual-booted off of the 256 GB card, I didn't anticipate running into boot errors with 32 GB CF cards but that's what I'm hitting.

I've purchased two different 32 GB CF cards, different brands and different speeds. I get "HDD Error" with both when trying to boot into the original firmware.
- https://www.amazon.com/Transcend-32GB-CompactFlash-Memory-TS32GCF800/dp/B00KSLLR12/ref=sr_1_1?crid=3F8E1XTUOWD74&keywords=transcend+compactflash+32gb&qid=1658809490&sprefix=transcend+compactflash+32gb%2Caps%2C128&sr=8-1
- https://www.amazon.com/Lexar-Professional-VPG-65-CompactFlash-LCF32GCRBNA1066/dp/B00IAYFD0K/ref=sr_1_5?crid=35U6822R67D8M&keywords=compactflash+32gb&qid=1658809465&sprefix=compactflash%2Caps%2C815&sr=8-5

In my attempts to get either one to work, I've eliminated the CF to IDE adapter as a problem--it's not. I can swap the adapter I'm using for the 32 GB mod into the existing 256 GB mod and it works just fine.

I'm beginning to wonder, does this have to do with the Rockbox dual-boot bootloader? The official Rockbox bootloader doesn't support it but another user here DM'd it to me and I've been using it in my 256 GB mod.

Any ideas are greatly appreciated.

[Festivus]

Just as an update to this, there might be something about the 32GB CF cards in general and the custom dual-boot bootloader has nothing to do with it. I did try switching the 32GB CF card into the X5 that has the 256 GB CF card and dual-boot. The X5 still throws up the HDD error with the 32GB card when trying to boot into the original firmware. It did not throw up the HDD error with the 256 GB CF card.

Further, I bought a CF/SD card adapter from iFlash and put a 32 GB SD card (full size SD card, not micro SD with an adapter) into that and it boots into the original firmware just fine.

Bottom line, 32 GB CF cards might be trouble or at least the ones that I bought and linked to above.