Xbox Trains Not Coupling In Training Centre Custom Scenario

Mk1 and Mk2 Coaches not coupling to each other in Scenario Planner on Training Centre. I have the Buckeye couplers out on both coaches however they are just bouncing off each other. The Mk2 is from NTP and the Mk1 is from SOS. I know they have different brake systems but this shouldn't affect the buckeye couplers from engaging.