This happened to me with KP-51 and KP-52, didn't test with stock.

I have a 4 partition 32Gb SD card.

If I access as mass storage, write some files to the sd card, then eject the unit, then disconnect the phone. Sometimes the new files don't show when the card is remounted to the phone, until the phone is rebooted.

They don't show even if I remove and put again the sd card.

¿Anyone else with this issue?