This answer is only relevant for the advanced menu under the Forecast Tools.
It can have various reasons, why a graph is not visible or changes, when you change the settings in the advanced menu.
Some typical errors and their possible solution will be described hereafter:
In many cases, the time interval of one variable is set to a different duration than for another variable. For example, if your wind power forecasts have a range of 7 days and your solar forecasts only of 3 days, changing from wind to solar may cause that the time range reaches too far into the future for the variable you have chosen.
Possible Solution: verify that location, variable and time interval are consistent and available. If this is not so, make the appropriate changes, e.g. change the time interval to 3 days or choose a time interval in the past and then step forward to see how much data there is available for this variable and location.
Sometimes there are things saved in the cache of the browser that need to be deleted to reload a forecast in a new time frame. This is the case, when your browser has had the interface open for a long time and you have not regularly pressed the load button or generated a new graph within the past 6 hours.
Solution: Empty the cache of your browser and log in and out of the interface.