We had this same problem, with "high endurance" TF/SD card adapters. We found that these adapters are mechanically off-size, and cause the card to be "locked" and cannot be unlocked, unless mechanically modified. We bought a bunch of chinese-copy adapters for cheap online, and all of these are working well. Problem was that "some" other slots may take these adapters properly, but some do NOT. Also the contact is erratic, so you may lose info, or stall the TF card, due to disconnect errors.