Setup Button Unresponsive after Waking from Stop Mode

When the Photon is put into sleep mode (stop mode) and woken up, the mode button is unresponsive. The button then cannot be used to enter listening mode. The button works fine after waking from Deep Sleep since the system is reset, but I think there is something going on with Stop Mode. This happened with the previous released firmware as well as the newly released 0.4.4.

In the code below, I get the following behavior:
-Briefly press the Setup button, Photon enters Stop mode after a few seconds
-Driving WKP High wakes the device, Setup button no longer works (unexpected)
-Can also wake from Stop Mode by pressing Setup button (unexpected, but nice) and then button works as expected

#include "core_hal.h"
void setup() {
pinMode(D7, OUTPUT);

void loop() {
    if (HAL_Core_Mode_Button_Pressed(100)) {
         digitalWrite(D7, HIGH);
        // delay before resetting debounce time
        // in case user is trying to enter Listening Mode
        for(int i = 0; i < 5; i++)
         digitalWrite(D7, HIGH);
         digitalWrite(D7, LOW);
     System.sleep(WKP, RISING);