Reproduction steps:
1. Create a new 3D project
2. Click Window > Package Manager
3. Click “+” > “Add package by name…”

Expected results: Package Manager window stays behind the input fields container
Actual results: Package Manager window is hidden behind the Editor, leaving only the “Add package by name…” input fields container in front of it

Reproduced with: 2022.3.10f1, 2022.3.13f1
Not reproduced with: 2021.3.31f1, 2022.3.9f1, 2023.1.20f1, 2023.2.1f1, 2023.3.0a15

Reproduced on: Ubuntu 23.10, Ubuntu 22.04
Not reproduced on: Windows 10 Pro 21H2