Bug in setWatch? Cross watching BTN3 and BTN4

Hi everybody,
I have this code:

clearWatch();
setWatch(() => {
  console.log('\-----');
  console.log('BTN3');
  btn3Handler()
}, BTN3, {
  debounce: DEBOUNCE,
  repeat: true,
  edge: "falling"
});
setWatch(() => {
  console.log('BTN4');
  btn4Handler()
}, BTN4, {
  debounce: DEBOUNCE,
  repeat: true,
  edge: "falling"
});

When I press BTN3 I get often (not always) get this in console:

\----
BTN3
BTN4

It looks like BTN4 fires together with BTN3.

The only workaround I found is this ugly one (clear watches before calling the handler and reattach them after):

clearWatch();
setWatch(() => {
  console.log('-----');
  console.log('BTN3');
  clearWatch();
  btn3Handler();
  addWatch();
}, BTN3, {
  debounce: DEBOUNCE,
  repeat: true,
  edge: "falling"
});
setWatch(() => {
  console.log('BTN4');
  btn4handler();
}, BTN4, {
  debounce: DEBOUNCE,
  repeat: true,
  edge: "falling"
});

The issue doesn't happen in the emulator, just on the real clock.

This is the gist with the complete code (the issue is at line 119):
https://gist.github.com/fbedussi/05f7bee30cf7fbc43a3dbfa728c5edb2

Is this a bug or am I missing something?

thanks and kudos for the project!