REST calls from business console works with Google Chrome but aren't working with Microsoft Edge/ IE

I have a custom BC Gadget which communicates to IS using REST. I am making this REST call using RestServiceProvider from BC (code below). I made sure I added required headers to be allowed on CORS extended settings on IS.
Although this works fine on Google Chrome, the same app isn’t working on Microsoft Edge and Internet Explorer 11.x
Extracted below from Microsoft Edge’s network logs:

My CORS extended settings on IS:

My code:

					.success(function (response, $scope) {
						$scope.searchResults.showResults = true;
					}).error(function (response, $scope, status, headers, config) {
						$scope.eventBus.fireEvent(NotificationConstants.ERROR, "INVOKING REST URL:" + $scope.URLS[REST_URL_TO_INVOKE].url + "----STATUS:" + status);

Fixed it.
I have noticed chrome sending request headers as “Accept,samlassertion” while Microsoft Edge and IE are sending them as “accept,samlassertion”
Capitalization of the 1st letter in “accept” is differing. I have modified my CORS suppored headers setting to have both of them. It worked.
Changed from:
watt.server.cors.supportedHeaders=Accept ,Cache-Control,authorization,samlassertion,Content-Type