Help! Cap stuck

Help! Cap stuck ( Dynavap / SundanceSmith ) When I was putting the tip into the main body I pressed down to hard I think and heard a click and now the cap won’t come off. The cap spins freely but I’ve tried everything I can think of to do, including the knife technique. You can see in the photo that the cap seems to have gone down quite far, further than normal. Thank you for any help! help,cap,stuck,help cap stuck