Slider marker not appearing online

What I used: Builder with custom code components
Psychopy version : v2020.2.9
operating system : macOS Big Sur version 11.1 Beta

Description of the problem:
I have a slider component in my routine, where I define in in both custom code and in builder as shown below:

#python side, begin routine tab 
slider.marker.size = (0.05, 0.05)

qLabs = ['LEFT: $20, RIGHT: $0', '$15/$5','$10/$10', '$5/$15', '$0/$20']
qTiks = (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)

slider = visual.Slider(win=win, name='slider',
        size=(1, 0.05), pos=(0, -0.35), units='height',
        labels= qLabs, 
        ticks= qTiks,
        granularity=1, style=['rating', 'triangleMarker'],
        color='Black', font='Arial',
        flip=False, labelHeight = .03)

//JS side, begin routine tab
qLabs = "'LEFT: $20, RIGHT: $0', '$15/$5','$10/$10', '$5/$15', '$0/$20'"
qTiks = "1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20"


demolabels = qLabs.split(",");
demoticks = qTiks.split(",");
demoticks = function () {
   var _pj_a = [], _pj_b = demoticks;
   for (var _pj_c = 0, _pj_d = _pj_b.length; (_pj_c < _pj_d); _pj_c += 1) {
      var i = _pj_b[_pj_c];
      _pj_a.push(Number.parseInt(i));
   }
   return _pj_a;
}
.call(this);

slider.size = [1.0, 0.05];
slider.setLabels(demolabels);
slider.setTicks(demoticks); 

The slider marker appears locally, but not online. I am able to click somewhere on the slider which then records my response (so my experiment doesn’t crash), but when I click the slider marker doesn’t appear. Am I missing something in my code?