I suppose you are talking about a SL 3242AI. If you are not explicitely recalling a scene, the SL AI mixers always show scene #1 ("zero out board", which cannot be overwritten !!!) after booting. But that does NOT mean that scene #1 is loaded, it just shows the name. The boards always remember their last settings. No information or setting gets lost when you shut down the board!
There is a workaround: When you have created, named and stored a scene, after booting your mixer the next time, select and load the scene you want to work with, change it - and save it again (overwrite it). I don't see any other way to save a scene without chosing a place (2-99) and writing its name again and again...
One tip: Create your own "zero out scene" with the settings you like to start with any time you want to build a new scene. This saves time and you can be sure that all input and output channels are "battle ready" in the way YOU want and need them to be. This is my scene #2 and I start everything from there.
Hope this helps.