RMX-1000 samples issue

I picked up a used RMX 1000 and cant get it to play samples. I have them loaded on the SD card, exported from Remixbox, the unit is switched to User and the card is inside. When I press the bank button all the sample lights go off and dont flash. Is there a specific format the card needs to be? Size restriction? It's a 64gb card. At first I thought the button may be broken but the lights go off when I press them.