Hi, I pull the lever to drop the 5 mudokens down to the lower level where they get gassed, lead them through the doors and up to the bird portal which gives me the powerup. It still says there are 3 mudokans

left on the level. I travel back down the lift and left along the floor until I reach a tube in the ground which 'supposedly' shoots me up to a higher platform but it just spits me back out on the ground??
Any ideas
Thanks.