R plot fonts not working; Access to font at 'about:blank' from origin 'http://0.0.0.0:8888' has been blocked by CORS policy

Notebook
1

I’m using the R kernel. My plots currently looks like this:

image
image840×840 18.8 KB
.

Obviously it’s a font issue. Now I notice in the network tab of my browser that I get this error:

Access to font at ‘about:blank’ from origin ‘http://0.0.0.0:8888’ has been blocked by CORS policy: Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, chrome-untrusted, https.

Now notably this is not because of the usual cross-origin security in Jupyter, because this happens even when I start the notebook with --NotebookApp.allow_origin='*'. Actually the problem seems to be to do with the fact that the webpage is requesting about:blank for a font in the first place.

Now I’m running Jupyter (6.1.1) on Ubuntu, through miniconda. I wonder if conda is somehow the culprit.

Does anyone have any ideas how to fix this?