I've been having issues getting the trainer function to work between two 14SG transmitters, I'm using the FUTM4405 cord, FUNC mode in the TRAINER menu for all channels on the master and a new default model on the slave. Testing on the ground worked fine and then when taxing out for takeoff and the instructor held switch SH to give control to the slave, there was no control on the slave (master still had control), we taxied back to the pits, shutdown, tested again and everything worked fine. Taxied back out again for take-off and it failed to give control again when instructor operated the switch, this time we could not get to to function at all even after shutting down and trying again. Thinking perhaps the switch was bad we configured the trainer function to use another switch and it still would not work. Additionally while in the TRAINER menu, page 4/4, the ACT field would never toggle to ON regardless of assigned switch/position it would stay at OFF, this was with the trainer cord plugged into both transmitters, slave power switch was off but transmitter was receiving power from the master and the trainer cord icon was displayed on the slave display screen. The master is on software version 6.0 and the slave 3.0, would this cause an issue?