Galaxy Tab A using an adaptor to be able to read my SD cards

[LPool]

I have a Galaxy Tab A and I have a bunch of Game Cameras out in the field. The game cameras take SD cards and the tablet takes MicroSD cards. I bought an adaptor that will take the SD card and you can insert it into my Tablet and I should be able to read my SD card out in the field. So I put the SD card into the adaptor....it doesn't seem to seat very well...no discernable click etc but having never used one before I don't know if this is normal. I then insert the adaptor into the SD slot in the tablet. I get a little green light that flashes for a minute (green light is on the adaptor) and it clicks into place. Instructions with the Tablet tell me to go into camera...settings and choose SD card. But once I go to settings...that option is grayed out and that tells me it's not recognizing the adaptor...I'm guessing???? Is there something else I should be doing or is the adaptor faulty. Any help would be appreciated....I will be more than happy to explain anything else more fully or send pictures if needed. Thank you for your help.