I bought a used BCD996XT and noticed while scanning a P25 system that the signal bar has all 5 lines for maybe an hour and then no lines for maybe two minutes and I have changed three antennas tried a Remtronic, telescopic and a outdoor antenna, I had tried the ID priority on and off still the same, Is this how it should operate for a P25 system and what could cause that issue, I don't know if it's this model it has the 1.06 firmware believe it was the last one for this model