I am monitoring a p25 digital system using a uniden bcd396xt and bcd996xt. The band plan for the system is 851.0625 with spacing of 6.25. Everything is fine but sometimes the scanner goes quiet and when I check the band plan it changed to 335.xxxx with different spacing. It has happened on both scanners but not at the same time. I don't know what is going on? Is it something inherent with uniden? Do I need an update?