Don't see button for "Adds one-click buttons to change diff style and to ignore the whitespace." #3551

Refined GitHub 20.9.11 Firefox 80.0.1 Chrome 85.0.4183.102

I have added the same personal access token to both Chrome and Firefox

I do not see the button for "Adds one-click buttons to change diff style and to ignore the whitespace." as shown here: https://user-images.githubusercontent.com/1402241/54178764-d1c96080-44d1-11e9-889c-734ffd2a602d.png

For example, on this page here I would expect to see it: https://github.com/seismic/engagement-service/pull/551/files

In Chrome, it's not working and I see the following error, and I do not see the error if I disable Refined GitHub:

refined-github.js:9838 Uncaught TypeError: Cannot read property 'cloneNode' of null at add (refined-github.js:9838) at runAdd (refined-github.js:4524) at applyChanges (refined-github.js:4476) at SelectorObserver.addRootNodes (refined-github.js:4742) at Array.processBatchQueue (refined-github.js:4433) at MutationObserver.handleMutations (refined-github.js:4457)

Interestingly, if I go to https://github.com/sindresorhus/refined-github/pull/3540/files in Chrome, I don't see the error but it's still not working.

In Firefox, it's not working and I only see the following error, but I see that error whether Refined GitHub is enabled or not:

Content Security Policy: The page’s settings blocked the loading of a resource at inline (“script-src”). onloadwff.js:71:798666