Yeah, that can happen. Often with deeper snow it will layer out. Colder below will keep it from sintering as quickly. If the snow continues, you can build a deep layer of heavy, non-sticky snow that is too cold to sinter. The upper layers can sinter a lot quicker. You can end up with layers of densly packed snow, followed by layers of loose granular like snow. Wetting the snow often helps. Or, simply exposing it to the outside air. Snow is a good insulator. Changing locations to a closed in area, or an open area may help.
Anyway, stakes can fail, often these simply do not have enough bite. I have seen it so granular, even a 6" parachute will pull loose. Under these conditions, a deadman is your only good choice. Often wetting the snow will only create a ball of ice that has no bite on the surrounding snow, just too granular. It really depends on conditions, as does most of winter camping. (I do not do winter camp anymore, getting too old for that stuff...)