On Windows 10 and Firefox 85, there seems to be a violation of the CSP wrt data: which is shown in the developer console. On macOS with Firefox 85 I cannot reproduce this issue, it might be something related to fonts.
Further investigation has shown that some browser extension (e.g. Grammarly) tries to load fonts from fonts.gstatic.com which is forbidden by our CSP. This is intentional. Thus, I'm closing this issue.
On Windows 10 and Firefox 85, there seems to be a violation of the CSP wrt
data:
which is shown in the developer console. On macOS with Firefox 85 I cannot reproduce this issue, it might be something related to fonts.