Reproduction steps:
1. Open the attached "IN-133535_Sandbox.zip" project
2. Ensure the Simulator window is present in the layout (otherwise see Notes)
3. Open the “Assets/Scenes/SampleScene.unity” scene. If it is already open, proceed to step 6
4. Close the Unity Editor
5. Reopen the project
6. Observe the Console window
7. Find the first purple log entry "Screen size" and compare it with the two cyan log entries, "Canvas Pixel Rect" and "Canvas Rendering Display Size"

Actual result: Resolution sizes differ
Expected result: Resolution sizes match

Reproducible with: 2023.2.0a16, 6000.0.70f1, 6000.3.10f1, 6000.4.0b11, 6000.5.0a8
Could not test with: 2023.2.0a12 (missing namespaces in script)

Reproduced on: Windows 11
Not reproducible on: No other environments tested

Notes:
- The Game view must not be present in the layout
- The "Simulator" window (Window > General > Device Simulator) must be present in the layout, with a device selected (in my case it's "Apple iPad (5th gen)")
- If you focus on the "Simulator" window throughout the process, the issue won’t reproduce unless you reopen the project
- Additional observation: on step 3, if SampleScene is opened for the first time after launching the project and the Device Simulator window has not been focused yet, all screen/canvas-related measurements will also report the fallback resolution (640×480). The reproduction above focuses on the mismatch where “Canvas.pixelRect” / “Canvas.renderingDisplaySize” remain at 640×480 while other values match