DART : I have a switch case of enums, which are buttons, but all cases are executing only once. It wont work the second time i click the same button - flutter

Question

Below is the switch case code, the main problem I have is, the code is fine for the first time that is appropriate output is rendered, but when I click the button (enum for example Scholarships) the code wont execute
PopupMenuButton(
onSelected: (Category selectedOffer) {
switch (selectedOffer) {
case Category.Scholarships:
{
offersData.showScholarshipsOnly();
}
break;
case Category.Investing:
{
offersData.showInvestingOnly();
}
break;
case Category.Courses:
{
offersData.showCoursesOnly();
}
break;
case Category.Discounts:
{
offersData.showDiscountsOnly();
}
break;
case Category.Finance:
{
offersData.showFinanceOnly();
}
break;
case Category.All:
{
offersData.showAll();
} break;
}
These are the functions which are linked to the above conditions
List<Offers> get offerList {
if (_showScholarships) {
return _offerList.where((selOffer) =>
selOffer.category.name.contains('Scholarships')).toList();
}
else if (_showCourses) {
return _offerList.where((selOffer) =>
selOffer.category.name.contains('Courses')).toList();
}
else if (_showInvesting) {
return _offerList.where((selOffer) =>
selOffer.category.name.contains('Investing')).toList();
}
else if (_showFinance) {
return _offerList.where((selOffer) =>
selOffer.category.name.contains('Finance')).toList();
}
else if (_showDiscounts) {
return _offerList.where((selOffer) =>
selOffer.category.name.contains('Discounts')).toList();
}
else if (_showAll) {
return _offerList.where((selOffer) =>
selOffer.category.name.contains(
'Investing,Finance,Discounts,Insurance,Courses,Scholarships'))
.toList();
}
return _offerList;
}