That is likely because the hubs are not able to provide adequate power. A USB extension cable should work.
It is also a bit complicated getting the sd card recognized by the computer.
when you plug it in to USB port, a USB symbol appears at the very top left of the screen. You need to touch and drag that down (tricky to do unless you have nice pointy fingers). Then you have to "unmount" the card in the dialogs that come up from that drawn down item. only then will it be seen by the computer. This is because the chip can't answer to two masters at the same time<G>.