How do you turn them on? The switch in the cab isn't clickable. Yet I've seen other NPC Talent 2's running with interior lights enabled, so I'm assuming there is another way around to turn them on.
Are you playing on the Epic version? Seems to be a bug introduced with the update to the Unreal Engine 4.26 - which will hopefully be fixed until the "official" release in 2 weeks *fingers crossed*