Been going through journey mode and I'm now stuck on this service. At the start at Manchester doors are open and no passengers board and the lights never change from red.
Search box is your friend... https://forums.dovetailgames.com/threads/ntp-passengers-not-boarding.18450/ (Spoiler: yeah, it's broken)
Even if you get the passengers to board their's no point anyway you'll never make it to Leeds, this is one of the broken services that gets stuck at a red signal just outside Leeds that never changes there's a couple of threads about it on the PS4 forum. It's been a known issue since last January and was carried over into the 2020 edition, looks like it will never be fixed.