changes made to pandas/core/groupby/ops.py/_call_cython_ops() and new file added in pandas/tests/groupby/test_groupby_last.py, issue pandas-dev#46409

Author: sydneyeh

pandas/core/groupby/ops.py

@@ -577,6 +577,11 @@ def _call_cython_op(
                     **kwargs,
                 )
 
+        if self.how == 'last' and dtype == bool:
+            for val in result:
+                if val > 1 or val < 0:
+                    result = values
+
         if self.kind == "aggregate":
             # i.e. counts is defined.  Locations where count<min_count
             # need to have the result set to np.nan, which may require casting,