How to reproduce:

1. Open the project "IN-66089"
2. Open the “SampleScene” scene
3. Select “Root“ GameObject from the Hierarchy window, open USD → “Export Selected With Children“ and save the file
4. Drag the saved file into the Project window and select it, in the Inspector window enable “Import” and press “Apply”
5. In the Project window extend the imported file and observe the material names

Expected result: Material names don’t have random numbers appended at the end of each name
Actual result: Material names have random numbers appended at the end of each name

Reproducible with: 4.0.0-exp (2023.2.7f1, 2023.3.0b4)
Not reproducible with: 3.0.0-exp.5 (2021.3.34f1, 2022.3.18f1)

Reproducible on: Windows 11 Pro (23H2)
Not reproducible on: No other environment tested

Notes:
-The packages which are used to reproduce this issue are: USD Core 1.0.0-pre.1, USD Importer 1.0.0-pre.1 and USD Exporter 1.0.0-exp.1
-The issue is not reproducible with the USD Experimental Package 3.0.0-exp.5 (which supports Unity 2019.4+ versions)
-The bug might have been caused by the package split and there is no correct way to verify if this is a regression