New ShaderGraph SubGraph remains dirty when the non-existing changes are discarded

How to reproduce:
1. Create and open a new project
2. Install the ShaderGraph package from the Package Manager
3. Create a ShaderGraph > Blank Asset and open it
4. Create a ShaderGraph > Subgraph and drag it onto the Shadergraph window
5. Double-click on the Subgraph to open it in the Shadergraph window
6. Observe the window name

Expected result: The Subgraph name has no asterisk at the end, indicating that it is not dirty
Actual result: The Subgraph name has an asterisk at the end, indicating that it is dirty

Reproducible in: 2022.3.58f1, 6000.0.39f1, 6000.1.0b7, 6000.2.0a4

Reproduced on: Windows 11 Pro (23H2)
Not reproduced on: No other environment tested

Notes:

• If the “changes“ are discarded, when the Subgraph window is opened again it will have the asterisk at the end of its name
• If the “changes“ are saved, when the Subgraph window is opened again, it will not have the asterisk at the end of its name
• In the user’s video, it is visible that this happens on developed Subgraphs as well
• Also, the user reports that sometimes an “ArgumentNullException“ error is thrown in the Console (Could not reproduce this locally)
• Might be reproducible with the black ShaderGraph Asset as well, not just SubGraph