String dtype: maybe_converts_object give precedence to nullable dtype

Author: jorisvandenbossche

pandas/_libs/lib.pyx

@@ -2699,16 +2699,16 @@ def maybe_convert_objects(ndarray[object] objects,
         seen.object_ = True
 
     elif seen.str_:
-        if using_string_dtype() and is_string_array(objects, skipna=True):
+        if convert_to_nullable_dtype and is_string_array(objects, skipna=True):
             from pandas.core.arrays.string_ import StringDtype
 
-            dtype = StringDtype(na_value=np.nan)
+            dtype = StringDtype()
             return dtype.construct_array_type()._from_sequence(objects, dtype=dtype)
 
-        elif convert_to_nullable_dtype and is_string_array(objects, skipna=True):
+        elif using_string_dtype() and is_string_array(objects, skipna=True):
             from pandas.core.arrays.string_ import StringDtype
 
-            dtype = StringDtype()
+            dtype = StringDtype(na_value=np.nan)
             return dtype.construct_array_type()._from_sequence(objects, dtype=dtype)
 
         seen.object_ = True