Sometimes those are FF bugs (or "bugs", but FF wants to fix them anyway), and you can report them to the firefox-run https://webcompat.com https://webcompat.com

Sometimes those are FF bugs (or "bugs", but FF wants to fix them anyway), and you can report them to the firefox-run https://webcompat.com https://webcompat.com through the menu. > People expect websites to work regardless of the device or browser they are using. When a site works in one browser but not another, that is most likely a web compatibility bug that we want to know about. I reported an inline-svg rendering bug in FF preview. It only took a minute or two, and a volunteer responding within a day that they had replicated the problem and moved it to a Github issue, which frankly amazed me.