Yes the drivers are different for the USB reader. It is fixable via firmware flash, but typically it is not advisable to flash firmware for RAMs on Jeep radios.
That being said, the correct drivers for the reader will be in the RAM download for a 2015. Flashing this firmware could result in a bricked radio. As another member said its advisable not to use 2015 radios in 13-14 trucks, but "some" have had success.
If you wish to avoid the risk, you can bypass the USB reader and plug a long USB extension cable directly into the back of the radio (gray plug) and put the other end in your glove box.
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