Sorry for the delay in the reply. I was away from the office for a mix of business travel and vacation.
Is the GEL file you are using: AM335x_15x15_EVM.gel ?
Have you tried using the on-board XDS100v2 on the EVM? I used the on-board and was able to connect just file with my AM3358EVM using the above GEL file for the A8.