Disable "recall" transfers

[radartc]

We've used the transfer.hang_up_after_success_trans = 3 on our T46S phones with great success. The transfer "Recall" doesn't happen anymore.

However, our receptionists, who transfer more than anyone else, have T54W phones. This parameter doesn't seem to solve the problem on the T5x series.

Is anyone aware of a parameter or other solution on that series of Yealink phones.


EDITED WITH T54W SOLUTION:

We had a newer T54W phone and the solution worked for it. So we updated all of our T54Ws to the newer firmware and then the Success Trans parameters worked correctly.