Can't edit python-file after opening a notebook in AzureML

When I create a python-file in my Azure-ML workspace and open it, I can write in it and save it no problem. As soon as I open a Notebook however it completely freezes. I can't write or delete anything. Even after closing all the tabs and reopening the python-file it's still frozen.
The only thing that helps is completely closing the workspace, going back to the portal and restarting the workspace.
This bug is 100% reproducible on my end.