Random Brave annoyance: when I look at the Mozilla form 990 in Brave, it prompts me to download the PDF. When I look at it in Chrome, in views it inline. I'm fairly certain Brave is capable of viewing PDFs inline; I could swear I've had some load. What gives?
Something throws off our Muon (fork of Electron) browser, but it isn't lack of content-type: or funky content-disposition: or whatever. Good news is it works the way you expect and the way it presents in Chrome (but still via PDF.js, we are not using the 0day factory known as pdfium that Chrome uses) in brave-core. Dev channel: https://brave.com/download-dev, beta channel: https://brave.com/download-beta.