It's clearly some fiendish Eventide plot to discredit the competition. I still think the problem is in your cabling, but giving the benefit of the doubt …
When the TF is OFF, relays disconnects the jacks from the electronics and connects input to output. What is known by some as "true bypass". The only thing that make it different from a piece of wire are a few small caps and inductors for EMI suppression.
It is possible that one of the relays is faulty, but in this case one would expect it to load the signal, causing a loss of tone. The effects from the other unit would still be there, but probably distorted in some way.
When you say the other delay pedals simply won't work, what exactly do you mean ?
Are you sure you have the simplest possible connections ?
