diff --git a/music_kraken/objects/collection.py b/music_kraken/objects/collection.py
index 2adb792..1e3ee89 100644
--- a/music_kraken/objects/collection.py
+++ b/music_kraken/objects/collection.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from collections import defaultdict
-from typing import TypeVar, Generic, Dict, Optional, Iterable, List, Iterator, Tuple, Generator
+from typing import TypeVar, Generic, Dict, Optional, Iterable, List, Iterator, Tuple, Generator, Union
 from .parents import OuterProxy
 
 T = TypeVar('T', bound=OuterProxy)
@@ -55,17 +55,19 @@ class Collection(Generic[T]):
 
             self._id_to_index_values[__object.id].add((name, value))
 
-    def _unmap_element(self, __object: T):
-        if __object.id in self._contains_ids:
-            self._contains_ids.remove(__object.id)
+    def _unmap_element(self, __object: Union[T, int]):
+        obj_id = __object.id if isinstance(__object, OuterProxy) else __object
 
-        for name, value in self._id_to_index_values[__object.id]:
+        if obj_id in self._contains_ids:
+            self._contains_ids.remove(obj_id)
+
+        for name, value in self._id_to_index_values[obj_id]:
             if name in self._indexed_values:
                 del self._indexed_values[name]
             if value in self._indexed_to_objects:
                 del self._indexed_to_objects[value]
 
-        del self._id_to_index_values[__object.id]
+        del self._id_to_index_values[obj_id]
 
     def _contained_in_self(self, __object: T) -> bool:
         if __object.id in self._contains_ids:
@@ -232,12 +234,14 @@ class Collection(Generic[T]):
             if existing_object.id == __object.id:
                 return
 
-            append_to._unmap_element(existing_object)
-            append_to._unmap_element(__object)
+            old_id = existing_object.id
 
             existing_object.merge(__object)
-            append_to._map_element(existing_object)
 
+            if existing_object.id != old_id:
+                append_to._unmap_element(old_id)
+
+            append_to._map_element(existing_object)
 
     def extend(self, __iterable: Optional[Generator[T, None, None]]):
         if __iterable is None:
diff --git a/music_kraken/objects/parents.py b/music_kraken/objects/parents.py
index 0ab6165..a90576b 100644
--- a/music_kraken/objects/parents.py
+++ b/music_kraken/objects/parents.py
@@ -3,9 +3,11 @@ from __future__ import annotations
 import random
 from collections import defaultdict
 from functools import lru_cache
-
 from typing import Optional, Dict, Tuple, List, Type, Generic, Any, TypeVar, Set
 
+from pathlib import Path
+import inspect
+
 from .metadata import Metadata
 from ..utils import get_unix_time, object_trace
 from ..utils.config import logging_settings, main_settings
@@ -187,12 +189,12 @@ class OuterProxy:
         if __other is None:
             return
 
-        object_trace(f"merging {type(self).__name__} [{self.title_string} | {self.id}] with {type(__other).__name__} [{__other.title_string} | {__other.id}]")
+        object_trace(f"merging {type(self).__name__} [{self.title_string} | {self.id}] with {type(__other).__name__} [{__other.title_string} | {__other.id}] called by [{' | '.join(f'{s.function} {Path(s.filename).name}:{str(s.lineno)}' for s in inspect.stack()[1:4])}]")
 
         a = self
         b = __other
 
-        if a._inner is b._inner:
+        if a.id == b.id:
             return
         
         # switch instances if more efficient
@@ -211,12 +213,15 @@ class OuterProxy:
                 collection.parents.remove(parent_collection)
             except ValueError:
                 pass
-
+        
+        old_inner = b._inner
         a._inner._refers_to_instances.update(b._inner._refers_to_instances)
 
         for instance in b._inner._refers_to_instances:
             instance._inner = a._inner
 
+        del old_inner
+
     def __merge__(self, __other: Optional[OuterProxy], override: bool = False):
         self.merge(__other, override)