It seems to me that simtrace looses a byte between 2 URB transfers from the device. To trace the problem down, I wrote a little test-program, running the same APDU against the smart card.
Interesting. This hasn't been seen so far.
Actually I think that's what I've noticed when I try listening to the communication between a LTE mifi and the SIM, except I was loosing two chars from time to time.
I never got to the bottom of the issue tough, but at least I can reproduce it locally and have a deeper look.
Cheers,
Sylvain