Same here. It keeps resetting to Google even though my iOS default is DuckDuckGo. In Firefox I have configured Kagi. I don’t even need to close the app, just not using it for long enough seems to reset it

The team wants to fix it with the next update.

A couple notes:

• Once the fix is released, you may still see an issue on your next immediate launch. However once you update your search engines again, the problem should no longer occur (IOW: you may need to fix your default engine one last time after the fix)
• In the meantime, users can also try deleting all their custom engines and re-adding them. This may resolve the issue for you as well without an update.

I am having this problem too: trying to use kagi search in firefox 144.2 and ipados 26.0.1, every time I close a firefox window search resets to duckduckgo. I suspect the problem might be in ipados settings->search, which does not include kagi as a choice, and instead has duckduckgo as the first in the list - this setting might be over riding my selection of kagi for search in firefox settings ?