Smaller hoses fit within the larger hose.
1/4 inch fits perfectly within 3/8 for example.... With weak intake vac at idle, a pcv doesn't really work as designed, it kinda flops around when it should be sealed. I just stuff things in the main hose until it works right..... kinda part of tuning.
I've heard some new cars don't even use a pcv, just a small restrictor. No expert on it all tho, just guessing my way to glory.