Garrett Headphones - Is this normal or not?

I will answer my own question and say simply that the replacement set I just picked up behaves the same way, so perhaps it is normal. Sounds fine with the stereo setting so all is well I guess..

I have the ACE 250 with the Garrett headphones. The mono doesn't work on my Garrett headphones either. Just the stereo. It's not the headphones. My old pair of headphones did the same thing with the ACE 250. I know nothing about electronics so maybe someone else will answer your question. I'm curious as to why the mono doesn't work. If I plug my old headphones into my stereo system it works on mono or stereo.