I experienced this last night. One time I woke up and tried to recall the dream and set my intention to remember it when I woke up and then went back to bed. Another time I woke up and got up to use the toilet without thinking about the dream and lost it. When I finally got up in the morning, I remembered my earlier dream and the one I was just in, but not the middle. It is hard to remember to stay still for a few seconds when waking up! One of my favorite techniques I've ever had work was the dream exit induction, where you stay completely still when you wake up and immediately do a WILD. Hoping I can get back to that soon.