It seems to be a handshake issue between the home theater and the USB drives.
As we can read from the specification of USB 2.0 at USB - Wikipedia, the free encyclopedia
higher maximum signaling rate of 480 Mbit/s (effective throughput up to 35 MB/s or 280 Mbit/s)
DTS HDMA has much higher bit-rate to be transferred. Most of the time it is handled by down-converting it to a lower bit-rate. You can try checking in the text file generated in separate folder when you play the USB from HT.
My Toshiba BD player and USB connection handles maximum 15 Mbps bitrate by automatically adjusting if the USB file has higher bit-rate.
Try down-converting it DTS Core using HomeTheater's settings and see if it works.