Hi - I upgraded from a 256gb SD card to a 400gb SD card. I’ve been transferring FLAC files to the new SD card and wanted to do a backup to my Mac. So I removed the new card from the phone and plugged it into the card reader on my mac but got a message that it was ‘unreadable on this mac’. Having tried this a few times I then loaded the old 256gb SD card and surprised when it worked fine. Any idea why the old card would work and the new one not? I also tried backing up the SD card to the internal memory of the phone and then re-formatted the card but still no go on the mac.
When I try to format again I don’t get the option to choose portable storage or phone storage, just ‘format’. When I unmount the SD and mount it again it comes up as ‘portable storage’ already…
I only vaguely recall how I proceeded with my own SDXC card on my really old Mac. From what I remember, the ExFAT format (for external storage formatting through a Mac) is the most compatible option. You might want to see if you can do this on the Mac (or via the card reader connected to the Mac), then put the card into the phone again and try if this has helped with making the card usuable on both devices.
As I said, my Mac is really old, so I cannot estimate how much more flexible more current versions of MacOS are with regard to this.
I re-formatted the SD card on the Mac using exFat and that seems to have worked. I’m currently copying files to it on my phone and will see if the card is still readable on the Mac afterwards. No reason why it shouldn’t be…