JD Rear Coupler Remotes do not release hose

[RancherGuy]

OK, I ran into a new one yesterday. My JD 6105 has 3 SCV "remotes" out back. I had sets of hoses plugged in, but when I went to separate them, one hose refused to disconnect. The tractor was turned off. I could hand-twist the hose in place, meaning no line pressure. I could push the hose into the connector, say 1/16", confirming there was no line pressure. But even yanking it as hard as I could with two hands, it refused to release. For the time being, to disconnect, I took two wrenches and unscrewed the Pioneer coupler from the hose, leaving the coupler in place.

This has never happened to me. Anyone have any insights? I looked at the JD coupler body and could not see anything that might look like a "release lever/override", like I have on my old (1979) International.