At seaford, the board seems to be working fine, except it shows a terminating train service as a service to seaford. After the allotted time it disappears, but the train isn’t at the station. So even when it says the train to seaford will be at e.g. 17:46, it won’t be there until 17:52 (which is when it’s supposed to be there). So the boards show a wrong destination and time.
Additionally, the time that is on the board is different to the one that you are instructed to leave at. I have found all of this after spawning on foot at seaford, at 17:45.