Hi Dale,
Welcome to the forum. I'm no expert, but I tried - unsuccessfully - to duplicate your situation. Perhaps I'm not understanding the conditions on your route.
Some users are confused by how Surveyor stores some information in a Route layer and other information in a Session layer. On the most basic configurations, normally all the permanent, stationary items like track work, buildings and scenery are placed using the "edit route" mode which will save them in the route layer. The locomotives, rail cars and any settings that you want to be associated with a specific session, are placed using the "edit session" mode in surveyor.
Perhaps this doesn't apply to you, but it is fairly easy to end up with locomotives and rail cars in the route layer and additions of track or track signals in a session layer. Having trains in both layers can produce confusing situations. Perhaps this isn't what's happening in your situation, but that was what came to mind reading your message.
Another thing to check is if there might be two switch levers or two track signals right on top of each other. The one on top hides the one below it, but they work against each other and behave unpredictably.
The two yellow lines above the locomotive likely are displaying how much fuel the locomotive has stored in it. The lines are green on my system. The numbers in these lines show how much is in the loco now followed by a slash and a larger number of how much fuel or sand it could hold if it was completely full. A diesel locomotive might be showing how much diesel fuel and sand it has. A steam engine would likely show how much coal and water is in the tender. As you operate the locomotive, the numbers before the slash should slowly decrease.
I'm sorry that I don't have a better answer for you. I hope this helps a little.
Happy Trainzing