Has the driver underlay toggle been removed from the released version of TRS2019, or has it been moved to another place? It was originally shown as below the three vertical dots on the lower right of the screen.
It's still there and has been moved - I had to hunt for it.
It's up on the bar above - I think it's on the window options - the icon with a slight border around it that's to the right. I'm not at my Trainzing computer at the moment and trying to picture the location in my mind.
