Problem with csp_extra

[ElModdy]

I'm trying to add Mathjax support to the theme by adding

tracking:
  script_src:
    - https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js

csp_extra: "script-src 'self' https://cdn.jsdelivr.net 'unsafe-inline'; style-src 'self' https://cdn.jsdelivr.net; font-src 'self' https://cdn.jsdelivr.net;"

to the config file. The problem is that the page is rendered with

<meta http-equiv="Content-Security-Policy" content="
...
script-src 'self'; script-src 'self' https://cdn.jsdelivr.net 'unsafe-inline'; style-src 'self' https://cdn.jsdelivr.net; font-src 'self' https://cdn.jsdelivr.net;">

where the first script-src 'self'; overrides the second one, so not allowing me anything more than self.
I'd really appreciate any kind of help.