I use Firefox as my main browser, and—through the Kagi extension—Kagi as my main search engine. Occasionally—I haven't yet gathered enough data-points to be wholly confident in this analysis, but my current best hypothesis is that it's after each time I update Firefox—my default search-engine resets back to Google, and I need to go into Firefox's settings to set it back to Kagi. It's still there in the list of options for default search engine in the settings; but it's no longer the selected one, until I go and re-select it. (At which point it stays there for the next while, until the next time the issue pops up.)
(I don't recall this having happened prior to maybe a few months ago. My best guess is that it started when I switched over to having Kagi installed in my search-engines-list via the extension, as opposed to via the non-extension-based process.)
More correct/desired functionality would be that, when I set Kagi as my default search engine in Firefox, it stays set to that.
