Monitor is very slow to respond to any button presses, seems to have gotten worse over time. I will press buttons 5-6 times while waiting/trying to get a response. Changing volume or changing between cameras (there are two) are both very slow. Scan still seems to work and doesn’t take too long to switch. Monitor unit is 1.5 years old, cameras are 1.5 years and 2.5 years old. Removing and reinstalling battery makes no difference.