Exactly the same problem here. I screwed it back in once or twice but not it will no longer catch the threads at all.
I also thought the screw had somehow become to short or threads stripped ,
but in fact the screw is now too narrow to catch the threads on the mushroom valve holder.
Perhaps the valve holder cracked/expanded slightly similar to what Eddie described above - but either way im stuck and open to ideas.
@stephen how did you fix your problem?
Quando isso acontecer, você poderá ver um gráfico da reputação que ele adquiriu ao longo do tempo.
Aqui está uma prévia de como será o gráfico:
Nenhuma reputação adquirida ainda.