HeaderAttribute is not displayed in the Inspector when using non-ASCII characters in the header's text

Reproduction steps:
1. Open the attached “IN-113379 HeaderAttribute Unicode Bug - FAV.zip“ project
2. Open the “SampleScene”
3. Select the “Bug Repro” GameObject from the Hierarchy
4. Observe the “Bug Repro Script (Script)” component in the Inspector

Expected result: "日本語　한국어　English" is displayed above the “Target” property in the Inspector
Actual result: No text is displayed above the “Target” property in the Inspector

Reproducible with: 6000.0.54f1, 6000.0.56f1, 6000.2.2f1
Not reproducible with: 6000.0.53f1, 6000.3.0a1, 6000.3.0a6
Fixed in: 6000.3.0a1

Reproducible on: Windows 11 Pro (24H2)
Not reproducible on: No other environment tested

Note: Reproducible in a new project