It’s not “updated” but rather “up to date” . Not sure what the Android app says in English specifically, but it’s a known problem that the app doesn’t follow the same “vocabulary” as Syncthing proper (see https://forum.syncthing.net/t/why-folder-inactive-during-upload/18299).
When it comes to the issue at hand though, I think it should be marked as “syncing” when you’re uploading something to the device, and “up to date” when you’re downloading from it (or when it’s just idle). I’m not 100% sure here, so please correct me if that’s not the case. I believe it also is “up to date” when exchanging just indexes, without any actual file transfer going on.