If the above suggestions have not fixed your problem ...

I have observed this behavior before in my own circuits. My problem was the “added” capacitors for the power supply were not immediately fully discharging below the brown-out range when I turned off the power. If I waited 30 seconds or so, they did eventually leak and everything worked great. If I turned the power back on sooner, sometimes it worked and sometimes it did not. Try measuring the voltage across the power supply and seeing what happens when you turn the power off. If the voltage hangs on, you can add a bleed resistor to your power supply so you do not have to wait. This worked in my case. Good Luck.

Paul Borgmeier
Salt Lake City, Utah
USA