GestureDetector not detecting inside of List.generate - flutter

Question

I have the following streambuilder below. If I put the GestureDetector on the Row widget (as indicated below) it receives the gesture. However, when I put it as shown, it does not. My current theory is that it is due to the List.generation there, however, I guess it could be because there are other widgets above it? It's in a Stack widget...although, if that's the case, why would the GestureDetector work on the Row widget?)
return StreamBuilder<List<List<Event>>>(
stream: widget.controller.stream.map(_filter),
initialData: Provider.of<CalendarData>(context).dayEvents,
builder: (context, snapshot) {
return Row(
//GESTUREDETECTOR WORKS HERE
children: List.generate(8, (col) {
if (col == 0) {
return Expanded(
child: GestureDetector(
behavior: HitTestBehavior.translucent,
onTap: () {
print('tapped: beer'); //<-- col
},
onScaleStart: (scaleDetails) => setState(() {
print('previousNumOfDays:$previousNumOfDays');
print('numberOfDays:$numberOfDays');
// dayIndexScaleCenter = col;
print('dayIndexScaleCenter: $dayIndexScaleCenter');
previousNumOfDays = numberOfDays;
}),
onScaleUpdate: (ScaleUpdateDetails scaleDetails) {
setState(() {
int newNumberOfDays =
(previousNumOfDays / scaleDetails.scale).round();
print('previousNumOfDays:$previousNumOfDays');
print('numberOfDays:$numberOfDays');
print('newNumberOfDays:$newNumberOfDays');
if (newNumberOfDays <= 14 && newNumberOfDays > 1) {
numberOfDays = newNumberOfDays;
}
});
},
child: Column(
children: List.generate(
hours.length,
(row) => Container(
height: Provider.of<CalendarData>(context).rowHeight,
decoration: BoxDecoration(
color: ColorDefs.colorTimeBackground,
border: Border(
top: BorderSide(
width: 1.0,
color: ColorDefs.colorCalendarHeader),
),
),
child: Center(
child: AutoSizeText(hours[row],
maxLines: 1,
group: timeAutoGroup,
minFontSize: 5,
style: ColorDefs.textSubtitle2),
),
),
),
),
),
);
}