diff --git a/pandas/core/apply.py b/pandas/core/apply.py
index 9c5806a3fe945..037c9c604161c 100644
--- a/pandas/core/apply.py
+++ b/pandas/core/apply.py
@@ -218,6 +218,8 @@ def apply_raw(self):
             if "Function does not reduce" not in str(err):
                 # catch only ValueError raised intentionally in libreduction
                 raise
+            # We expect np.apply_along_axis to give a two-dimensional result, or
+            #  also raise.
             result = np.apply_along_axis(self.f, self.axis, self.values)
 
         # TODO: mixed type case
diff --git a/pandas/core/groupby/groupby.py b/pandas/core/groupby/groupby.py
index 204346bb7b741..8674f0fd4985a 100644
--- a/pandas/core/groupby/groupby.py
+++ b/pandas/core/groupby/groupby.py
@@ -795,13 +795,13 @@ def _try_cast(self, result, obj, numeric_only: bool = False):
                 # Ensure we localize to UTC first before converting
                 # to the target timezone
                 arr = extract_array(obj)
-                try:
+                if not is_datetime64tz_dtype(result.dtype):
+                    # arr may have already been cast back to tzaware in _try_cast
                     result = arr._from_sequence(result, dtype="datetime64[ns, UTC]")
                     result = result.astype(dtype)
-                except TypeError:
-                    # _try_cast was called at a point where the result
-                    # was already tz-aware
-                    pass
+                else:
+                    result = arr
+
             elif is_extension_array_dtype(dtype):
                 # The function can return something of any type, so check
                 # if the type is compatible with the calling EA.