Since updating to FF6 6.4.2 I have had problems with my micro SD cards not being able to be read by my Mac's, regardless of plugging in the Anafi to read them or using a SD card adapter to read them. I have been transferring to my Linux laptop, then on to a USB stick, then to my iMac. How convoluted is that?
I just discovered that I can no longer format my micro SD cards using the official SD card formatter any more & that was the source of my woes!
What worked for me was to erase & repartition the micro SD cards in my iMac as FAT32 format using Disk Utility, then following through
@CTF1414 's instructions in the first message but stopping at step 7! You need to do a "Quick Format" in the Anafi, if you do a "Full Format" in the Anafi it will not be able to be read by a Mac...
I now have my collection of micro SD cards all able to be read by my Mac's (laptops & desktops).