The rubber seals on both of my blades come out pretty much every time I use the Nutribullet. I stick them back in, trying to poke them back down. There's really no fix, but just sharing. Also, untwisting the blades is SO HARD, but if you don't twist them on tight the thing leaks. I'm a guy and I work out, but I still struggle sometimes untwisting and removing the blades. Hopefully they come out with a better design.
I would suggest reaching out to customer service to help trouble shoot or get you a new blade: 1-855-346-8874