Unfortunately, it is not FOSS but I find Obsidian with kanban plugin a killer. They do release their Android app from Github, and some custom ROMs allows you to disallow network permission. Also for Linux version, you can use Flatpak release and run it without network permission. Not very ideal, but I find it working for me.

Siyuan note is FOSS and AFAIK does everything Obsidian does.