Django: one of pages is not opening

Solution 1:

In your urls.py both about_me and portfolio points to the same function.

path('about_me/', views.Portfolio.as_view(), name='about_me'),
path('portfolio/', views.Portfolio.as_view(), name='portfolio'),

Both urls points to your Portfolio view. So change views function name accordingly in your urls.py.

path('about_me/', views.YourAboutMeView.as_view(), name='about_me'), #<---- change this view name accordingly
path('portfolio/', views.Portfolio.as_view(), name='portfolio'),

Solution 2:

May be beacuse when have in app urls.py

 path('about_me/', views.Portfolio.as_view(), name='about_me'),
 path('portfolio/', views.Portfolio.as_view(), name='portfolio'),

you have used

views.Portfolio

for both about_me and portfolio