I think your approach should work, but it might be easier to right-click the links, and use “save link as”, which should allow you to download the LS file.
Thanks for the report, there was indeed a bug submitting certain answers after matching, but I believe it should be fixed with this new version: Bunpro v0.0.5. This also includes an option to automatically show the answer after you say ”だめ” to mark a card wrong.
Please don’t hesitate to let me know if you see any other problems