Try mo reformat using SanDisk formatter tool..
https://kb.sandisk(dot)com/app/answers/detail/a_id/14827/~/using-sd-formatter-tool-to-restore-full-capacity-on-sdhc%2Fsdxc-cards
Pag reformat mo at di nakawala yung mga files,
that means tigok na si SD card kasi nareach niya na lifespan niya..
Yan nangyari sa dalawa ko ding microSD cards..