I just noticed my Bubblebubs had started doing the same thing, though not as bad. I was also noticing an ammonia smell to some of the other nappies when I was changing DD so did a strip wash.
Did a rinse, warm wash with a tablespoon of dishwashing liquid, then another wash cycle with nothing.
The Bubblebub is back to it's beautiful soft self. Hopefully the ammonia smell will go out of the other nappies too.