Template Container is created instead of Instance Element in UI Staging Mode

Reproduction steps:
1. Create a new project
2. Create Instance Element (GameObject > UI Toolkit > Standard Elements > UI Library… > UnityEngine > UIElements > Instance)
3. Create UI Document
4. Observe newly created Element in the Hierarchy

Actual result: TemplateContainer is created in the Hierarchy instead of the Instance Element
Expected result: Instance Element is created in the Hierarchy

Reproducible with: 6000.6.0a7, 6000.6.0b5, 6000.7.0a3
Couldn’t reproduce with: 6000.0.80f1, 6000.3.20f1, 6000.5.5f1, 6000.6.0a6 (No Standard Elements option)

Reproduced on: Windows 11, macOS Tahoe 26.5 (M4)