Nomad II problem - Only runs to 19-20 and wont build pressure higher

I have had this Nomad II since March. It's always ran pretty well. All of a sudden today, it will get up to 19-20 on the meter and wont build pressure. It would usually run 23-24 when it was working. Wondering if anyone has had this issue that got it fixed.

Make damn sure to get a brand new warranty exchange right before the warranty is up otherwise you will be sorry.
 
When I get home from holiday, i'm going to check mine. Last time I used it, it wouldn't build pressure, 12 -14 on gauge. I tried running it, holding my finger over the end and letting the pressure that had built up out suddenly a couple of times, and then it built pressure. I was 2 fills over the purge system service and so did this after the next fill, and got a good little amount of silicone out, so I wonder if this builds up, and won't seal somewhere to pressurize?