replace port number correctly

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

authentik/providers/oauth2/models.py

@@ -271,19 +271,23 @@ def jwt_key(self) -> tuple[str | PrivateKeyTypes, str]:
 
     def get_issuer(self, request: HttpRequest) -> str | None:
         """Get issuer, based on request"""
+        full_url = ""
         if self.issuer_mode == IssuerMode.GLOBAL:
-            return request.build_absolute_uri(reverse("authentik_core:root-redirect"))
-        try:
-            url = reverse(
-                "authentik_providers_oauth2:provider-root",
-                kwargs={
-                    "application_slug": self.application.slug,
-                },
-            )
-            return request.build_absolute_uri(url)
-
-        except Provider.application.RelatedObjectDoesNotExist:
-            return None
+            full_url = request.build_absolute_uri(reverse("authentik_core:root-redirect"))
+        else:
+            try:
+                url = reverse(
+                    "authentik_providers_oauth2:provider-root",
+                    kwargs={
+                        "application_slug": self.application.slug,
+                    },
+                )
+                full_url = request.build_absolute_uri(url)
+            except Provider.application.RelatedObjectDoesNotExist:
+                return None
+        if request.is_secure():
+            return full_url.replace(":443", "")
+        return full_url
 
     @property
     def redirect_uris(self) -> list[RedirectURI]: