I just had this pool installed last year. Last year my clean pressure reading was 15psi and when shut off it would go to 0. I just opened the pool last week after my first winter owning a pool. Now the gauge reads 25 in operation but only goes down to 10 when it’s turned off? I did backwash and rinse cycle the filter thinking that was it but no change. Did the gauge go bad that quickly or is there something I’m missing here?