That's weird- you shouldn't be able to go directly from a clear to a stop like that. Another train must have entered the block beyond the red signal at exactly the time you crossed the clear. Shouldn't the AI dispatcher prevent that, though?
Yeah that problem has been mentioned before. It's a tricky one. I actually think the signalling is correct with the light signal protecting the tunnel mouth (maybe with operations from the loop). But maybe DTG have set the block wrongly, the light signal and the previous semaphore should perhaps be linked and show the same aspect and not be considered as a separate block (that should start after the tunnel mouth). That way you would be held at the semaphore with maybe a distant prior to that giving you warning.
I've been caught at that signal and one the other side of Marsden. All greens then red. No chance of stopping. Thread here: https://forums.dovetailgames.com/threads/19-48-manchester-to-leeds-express.17422/