I have had a little issue with mine, and figured out a work around.
If I have my bluetooth set up, like if I get to the site first and am listening to tunes from my phone, and able to answer the phone, and keeping my ears warm, and another helmet tries to link, or me to them, it doesn't work. I turn off the bluetooth, link the comms, then turn on my blue tooth again. Not a big deal if everyone stays in range, but if someone goes somewhere in the truck, its a bit of an inconvenience.
This happened the day before yesterday. It didn't link while BT was activated to either of the other two units. Erik is out of town, so we didn't see how it worked with having all three on. Friday, we will.