I have keywords associated with some of my bookmarks in Firefox, and on the desktop they work great. They were working great on the mobile app for a while too, but that stopped several weeks ago. I don't know exactly when. That is, I have a bookmark pointing to https://law.cornell.edu/uscode/text/%S. I associate that with the keyword usc. On desktop Firefox, if I type "usc 18/1001" into the address bar, I go directly to https://law.cornell.edu/uscode/text/18/1001. But on mobile Firefox, my query gets passed to my default search engine (DuckDuckGo), so I get search results from DDG instead. This makes me sad.