You know what...the same card has migrated with me from WP7 to 8.0 to that 8.0 device being upgraded to 8.1 then 10. Still, I had to put it back in that last device to get it unlocked for use on my current phone (Lumia 650). Otherwise the phone refused to recognize it, wanting to immediately format it, and ditto my Windows 10 and Linux desktops. On Linux at least, it did show two separate encrypted partitions, so given what you said that makes sense.