On both the wagon loading tutorial, and services with loading, whenever the pumping hose has been attached, the instant the player climbs back to the control area by pressing "Y", the hose de-attaches itself. The wagons can still be filled in this state, though the whole thing looks ridiculous.
You think that's bad, my GP9RM's ammeter drops for nothing pulling cars. Plus in addition to this, the whole signalling system does not conform to CROR rules. And I'm on an Xbox One X.
Graphically, this leads to some confusion, because to LOOKS like the hose is not attached when, in fact it is. In order to turn the pump off, you must pick up and subsequently let go of the nozzle. I suspected something was amiss when I couldn't close the hatch. Picking up the hose, that isn't attached to anything, resolves that issue.
The loading issue appears to have been patched with yesterday's update, loading pipes now remain attached.