I recently upgraded firmware to 15.03 on two different PTP 450 5.x links. both had great signal on 5.4 band, but after update they will not connect on 5.4, switch to 5.7 they work fine. When they are on 5.4 the Slave end will connect for about 2-3 seconds and disconnect I will see a "BH RERANGE" status for a second or two, then the status goes to idle and then the process repeats.