AL Priority won't start properly when facing a wall

[BestRadarDetectors]

My ALPs make a different beeping sound when the parking sensors are going off. It's not a double beep but a single. Perhaps that has changed recently as I disabled the parking sensor alerts

I have spoken to this customer and his ALP's were alerting to interference detected. Double Beep at Startup error. When he backs away the ALP will start normally and the ALP self test will pass with no errors.