When I open a new Jupyter notebook using the command palette in VS code, it opens in the new interface (see https://code.visualstudio.com/blogs/2021/08/05/notebooks).
However, when I close the file and then reopen it, the file opens in the old interface, along with a depreciation warning.
How can I always use the new interface (without using VS Code Insiders)?
Your vscode probably still has the old editor as default for the noteboook extension you are trying to open. You can change the default editor in the IDE itself, with a workspace containing any file with such an extension. Right-click on one of the files with the extension you want to set to the new VSCode editor and select "Open With...".
Select "Configure default editor for '*.ipynb'..."
Finally, select "Jupyter Notebook, Built-in"
Now VSCode should always open notebooks with that extension in its new UI, unless you specify another editor with the Open With option.
