This is clearly an issue with Samsung somehow. I don't know if it's hardware or mechanical in nature (e.g. the spring or sleeve it goes into) or what. But if you google it, this is the SAME problem that plagued s3 and n2 owners. It doesn't affect everyone, and none of these factors are consistent:
- rooted vs. not rooted
- stock vs. AOSP
- class of SD card
- SD card brand (unless they all share the same underlying memory chip maker like Micron, etc, but no one has demonstrated that)
At this point, I'm afraid to even buy and put in a new card as it's eaten 2 of mine. I'm tempted to just go without an sd card at this point and just pull ROM backups/etc off the phone if/when I do a TWRP backup or something to keep the internal storage from filling up (since we have a whopping 10G of the 16G left over on the sdcard).
"I drank what?" -Socrates