Problem with setWatch on MDBT42Q

Hi,

I'm just getting starting with Espruino and I'm new to the setWatch function.

I have a MDBT42Q board that I want to read a button input from a capacitive touch sensor momentary switch from Adafruit (https://www.adafruit.com/product/1374). The code is as follows:

digitalRead(D28);
pinMode(D28, "input_pulldown");

setWatch(function() {
  digitalPulse(LED2, 1, 50);
  console.log("Pressed");
}, D28, {repeat:true, debounce:50, edge:"rising"});

If I connect briefly D28 to the 3.3V pin it works as expected.
But if I connect it to the output of the momentary switch (and I touch the switch) it doesn't.

I played with the pin D28 as an analog input and I have observed the following:
D28 reads 0.99 when connected to the 3.3V pin.
D28 reads 0.97 when connected to the output of the switch (and the switch is touched). This corresponds to around 3.22V.
D28 reads close to zero when the switch is in open position (no touch).

All results make sense and in analog mode I can read the sensor being touched.
But it appears that the setWatch function interprets in digitalRead mode 0.99 as high but 0.97 as low, as if the threshold for a high would be beyond 0.97.

Is this an expected behavior? Can this threshold be changed? I would have expected that anything beyond 1V would be detected as high.

The end application is a bluetooth media controller with a play/pause touch sensor and a next touch sensor to be integrated in the handle of my rowing machine, so that I can control playback while rowing.

Oscar.