Random button presses

Other Hardware General Electronics
4

All I see is that your button reading solution checks the status of the button at 50 ms intervals. That is not really debouncing.
This example I use from time to time. It requires that any change of state is stable for a defined number on milliseconds before accepting it and so is quite suited for noisy environments.

bool  getKey() {
  // get debounced key press
  static bool currentKeyState = HIGH ;
  static bool newKeyState = HIGH ;
  static uint32_t newKeyStateAtMs = millis()  ;

  bool dr =  digitalRead(inputPin) ;
  if ( dr != newKeyState ) {
    newKeyState = dr ;
    newKeyStateAtMs = millis() ;
  }
  if ( currentKeyState != newKeyState && millis() - newKeyStateAtMs > 50) {   // configure this as required.
    // debounce: accept only a mature change ( > X ms )
    currentKeyState = newKeyState ;
  }
  return currentKeyState ;
}