errrr...
A major line has made a large loss, & that was up to March 2019
https://www.railforums.co.uk/threads/west-somerset-railway-lost-£800k-last-year-bbc-news.195437/
They've made changes for 2020 to reduce costs, but there's still the 2019 season to be accounted for.
Or the Bluebell, up to December 2018
https://www.railforums.co.uk/threads/bluebell-railway-reports-a-loss-of-£220-000.187087/
SDRplc (retail & catering) made a loss up to December 2017, they've since become a Community Benefit Society (May 2019) & haven't got any publicly available accounts.
The owning trust, to year end December 2018, made a loss.
They had the 'missing floor' incident in June 2017. Which was then on the news in Jan & May 2018. They were fined £40k in 2018, don't know when that has to be paid. I'm sure that hit visitor numbers.
We are now entering the closed season, when for 3 months there's no income apart from Santa specials for many lines, yet they still have costs.
It's also the time when infrastructure works are more intensive, which is cash going out.
You also need to remember that any accounts you look at currently are going to be for the 2018 season/year. 2019 could well be worse.