diff --git a/sentry_sdk/api.py b/sentry_sdk/api.py
index 166dddd199..639d0fe5dc 100644
--- a/sentry_sdk/api.py
+++ b/sentry_sdk/api.py
@@ -295,7 +295,7 @@ def start_transaction(
     **kwargs,  # type: Any
 ):
     # type: (...) -> Union[Transaction, NoOpSpan]
-    return Scope.get_current_scope().start_transaction(transaction, **kwargs)
+    return Scope.get_isolation_scope().start_transaction(transaction, **kwargs)
 
 
 def set_measurement(name, value, unit=""):
@@ -318,7 +318,7 @@ def get_traceparent():
     """
     Returns the traceparent either from the active span or from the scope.
     """
-    return Scope.get_current_scope().get_traceparent()
+    return Scope.get_isolation_scope().get_traceparent()
 
 
 def get_baggage():
@@ -326,7 +326,7 @@ def get_baggage():
     """
     Returns Baggage either from the active span or from the scope.
     """
-    baggage = Scope.get_current_scope().get_baggage()
+    baggage = Scope.get_isolation_scope().get_baggage()
 
     if baggage is not None:
         return baggage.serialize()
@@ -339,6 +339,6 @@ def continue_trace(environ_or_headers, op=None, name=None, source=None):
     """
     Sets the propagation context from environment or headers and returns a transaction.
     """
-    return Scope.get_current_scope().continue_trace(
+    return Scope.get_isolation_scope().continue_trace(
         environ_or_headers, op, name, source
     )
diff --git a/sentry_sdk/scope.py b/sentry_sdk/scope.py
index 2121dcfe8d..efc816b6ba 100644
--- a/sentry_sdk/scope.py
+++ b/sentry_sdk/scope.py
@@ -469,7 +469,7 @@ def generate_propagation_context(self, incoming_data=None):
                     self._propagation_context,
                 )
 
-        if self._propagation_context is None and self._type == ScopeType.CURRENT:
+        if self._propagation_context is None and self._type != ScopeType.CURRENT:
             self.set_new_propagation_context()
 
     def get_dynamic_sampling_context(self):
@@ -616,6 +616,21 @@ def iter_trace_propagation_headers(self, *args, **kwargs):
             for header in self.iter_headers():
                 yield header
 
+    def get_active_propagation_context(self):
+        # type: () -> Dict[str, Any]
+        if self._propagation_context is not None:
+            return self._propagation_context
+
+        current_scope = Scope.get_current_scope()
+        if current_scope._propagation_context is not None:
+            return current_scope._propagation_context
+
+        isolation_scope = Scope.get_isolation_scope()
+        if isolation_scope._propagation_context is not None:
+            return isolation_scope._propagation_context
+
+        return {}
+
     def clear(self):
         # type: () -> None
         """Clears the entire scope."""
@@ -964,20 +979,20 @@ def start_span(self, instrumenter=INSTRUMENTER.SENTRY, **kwargs):
         if instrumenter != configuration_instrumenter:
             return NoOpSpan()
 
-        scope = Scope.get_current_scope()
-        span = scope.span
+        # get current span or transaction
+        span = self.span or Scope.get_isolation_scope().span
 
         if span is None:
             # New spans get the `trace_id`` from the scope
             if "trace_id" not in kwargs:
-                traceparent = self.get_traceparent()
-                trace_id = traceparent.split("-")[0] if traceparent else None
+
+                trace_id = self.get_active_propagation_context().get("trace_id")
                 if trace_id is not None:
                     kwargs["trace_id"] = trace_id
 
             span = Span(**kwargs)
         else:
-            # Children take `trace_id`` from the parnent.
+            # Children take `trace_id`` from the parent span.
             span = span.start_child(**kwargs)
 
         return span