Fonly, congrads !
Try this.........ALWAYS keep button fully depressed until blade (either side) is fully "tucked" into handles........then release button.
If you have trouble getting saw all the way into handles......simply reach out to end of blade at the gut hook and pull up a bit until saw is in, then release button.
I always pivot slowly all the way around until my blade is secure and locked into handles. Once you practice a bit it will become second nature I'm certain.
Another tip, when you saw, steady even strokes work best, and let the saw work, don't push down too hard or the needle sharp teeth will just embed themselves deeper into the wood making the saw harder to move through the slot............even and steady, you'll be surprised.
You now have a straight knife that can do almost anything that other 5 inch blades can do.........except your knife can saw poles for shelters or firewood, make precise traps or anything else you might need to saw around the camp up to about 5 inches.
Most people tell me they never think about the hidden saw until they need a saw.