I have a fifthwheel part that uses connection_1_1_connected, but it always returns zero.

In this image, the connection_1_1_connected textObject is showing the value on the fifthwheel part.

The part tree is Truck -> Subframe -> Fifth Wheel. The connection and towing work fine, it is just the variable that doesn't seem to work.

I can confirm that this variable works in other scenarios, like using it to apply the parking brake on disconnected trailers (like in #1841 ).