ProxyAccessor driven by referenced transform does not evaluate after re-opening scene

**Describe the bug**
If I create a proxyAccessor to drive the xformOp properties on an Xform prim from a referenced Maya transform, it works as expected in the current session. However, once your save and re-open the scene, it no longer works.

**Steps to reproduce**
Steps to reproduce the behavior:
1. Create > Universal Scene Description > Stage With New Layer
2. Add an Xform prim
2a. Add a Cube prim as a child of the Xform prim (for visibility)
3. Reference a file with a single transform
4. Create a proxyAccessor using mayaUsd.lib.proxyAccessor.connectItems
5. Move the referenced transform; observe the Xform prim follows
6. Save and re-open the scene
7. Observe the Xform prim is at origin, and no longer follows the referenced transform.

An example setup is provided in the attached scene.

**Expected behavior**
A proxyAccessor to drive the xformOp properties of an Xform prim, driven by a referenced Maya transform, should still work after the scene is re-opened.

**Attachments**
[scene.zip](https://github.com/user-attachments/files/16820459/scene.zip)

**Specs (if applicable):**
- Rocky 9.3
- Maya 2023.3
- MayaUSD v0.26.0
- Pixar USD 0.21.11