Cobra Power Save question.

Hello all new to the forum been searching for some info on a pair of Cobra PR-650 WX radios that I have. They are equipped with a “power save” mode that it defaults two after 10 seconds of inactivity. It works on one of the radios but on the other there seems to be a faint signal that comes through when you look at the antenna meter ever 2 seconds or so. I can’t hear anything but because it is happening it never goes to power save mode. When I switch to the FRS channels doesn’t happen and will go into power save…only happens on frs/gmrs or gmrs channels. This causes the radio to drain the batteries rather quickly. Has anyone ever experienced anything like this? Or maybe there is a way to adjust the sensitivity? It’s frustrating to drain the batteries on one in 2hrs while the other could last 5x longer.
Any tips appreciated,