Try lowering your bottom temp to ensure the dewpoint doesn’t over-shoot. You need to ensure the scale of the graph can accomodate the temps your station is reporting. As for auto-scale graphs, there should be some threads about it in the forum. I have the worst luck using the search function, but I will have a go and see if I can find the thread and post a link if I find anything.
edit: Here is a thread that describes how to change your settings. http://discourse.weather-watch.com/t/8550