I went searching online to see if there was a way to check the fluid levels without the dipstick, to say know where the level should be at from the hole where the tube inserts and couldn't find anything!
I didn't think about it till now, but one thing you can do since it's a van body is pull the dog house where you can access the brackets that hold the dipstick tube in place, loosen them so you can actually pull the tube out of the trans and just have it hang aside the trans. put the stick in place and look to see how far it sticks out. if it goes further than the depth of the pan or if about the pan bottom area.
on vans I know the tubes are long and curvy, I recall some of them just being stubborn to get the stick in all the way and sit right due to all the curves and bends in the tube. But this would confirm if it's the stick too long or just the tube bends and whatnot.