For a notebook using image display with jupyter_firefly_extensions, image display does not work after the Python notebook kernel is restarted and the notebook is re-executed. When the Jupyterlab browser tab is reloaded, the notebook executes fine again.

To reproduce, execute slate-widget-demo.ipynb that is one of the examples for the extension. Run all the cells once; then restart the Python kernel for that notebook; then re-execute. Image display does not work the second time around.

I have checked that channel and render_tree_id do not change.

For users, the workaround is to restart the Python kernel and to reload the browser tab, when wishing to re-execute a Firefly notebook.