Flutter State using ChangeNotifier doesn't maintain State - flutter

Question

TLDR, I'm building a Stock Screener and when I access a table from one widget it renders proper state, but when called from within the class the state defaults to initial values (I think).
Overall design concept is user configures their stock screener and hits "Screen" button at bottom of page.
Here's a View Example. This is the Market Cap Selector Widget that uses Consumer to retrieve state from the class ScreenerController extends ChangeNotifier
class CapSelectorWidget extends StatelessWidget {
Widget capButton(capSelection) {
return Consumer<ScreenerController>(builder: (context, capData, child) {
return GestureDetector(
child: Container(
padding: EdgeInsets.all(12.0),
margin: EdgeInsets.all(6.0),
decoration: BoxDecoration(
color: capData.getColor(capSelection),
borderRadius: BorderRadius.circular(8.0),
),
child: Text(
capSelection,
textAlign: TextAlign.center,
),
),
onTap: () {
capData.toggleCapSelection(capSelection);
},
);
});
}
Both methods getColor and toggleCapSelection ultimately reference and/or update the below _capColorList. Here is the code for the _capColorList and toggleCapSelection
class ScreenerController extends ChangeNotifier {
//////////////////////
// Market Cap Widget
//////////////////////
Map _capColorList = {
'Micro Cap': {
'isSelected': true,
'selectedColor': Colors.teal[300],
'unSelectedColor': Colors.white38,
},
'Small Cap': {
'isSelected': true,
'selectedColor': Colors.teal[400],
'unSelectedColor': Colors.white38,
},
'Mid Cap': {
'isSelected': true,
'selectedColor': Colors.teal[500],
'unSelectedColor': Colors.white38,
},
'Large Cap': {
'isSelected': true,
'selectedColor': Colors.teal[600],
'unSelectedColor': Colors.white38,
},
};
void toggleCapSelection(String capType) {
// Flip bool selected value
_capColorList[capType]['isSelected'] =
!_capColorList[capType]['isSelected'];
notifyListeners();
print(capType + ' ' + _capColorList[capType]['isSelected'].toString());
};
etc...
So far so good. When user hit's a Cap Bucket, it'll toggle state and the color will update.
Now when user hits "Screen" (ie Submit) at bottom of page, this code is implemented.
child: FlatButton(
child: Text('Screen', textAlign: TextAlign.center),
onPressed: () {
ScreenerController().screenStocks();
//Todo: Figure out why Provider.of doesn't work on Screen Button
//Provider.of<ScreenerController>(context, listen: false)
// .screenStocks();
},
),
I implement the following code to create a list of the Market Cap Buckets into a List.
My hypothesis is that because Provider.of isn't working for the FlatButton (it's in the same ChangeNotifierProvider tree), that I'm inadvertently creating a new instance.
Map screenerQueryBuilder() {
//If Cap Button is selected, add it to selectedCaps
List<String> selectedCaps = [];
for (String cap in _capColorList.keys) {
print(cap + _capColorList[cap]['isSelected'].toString());
if (_capColorList[cap]['isSelected']) {
selectedCaps.add(cap);
}
}
print(selectedCaps);
The problem is, even if let's say the Buttons "Mid Cap" and "Micro Cap" are not selected when the user hits Screen, when I iterate over _capColorList.keys the values are always true, and therefore they are always added to the selectedCaps List.
Might anyone know why this is?
Thank you in advance!