Hello, I would try updating Luma3DS.
Download the latest version of Luma below.
https://github.com/AuroraWright/Luma3DS/releases/tag/v6.6
Simply drag and drop the "arm9loaderhax.bin" file from the archive you downloaded to the root of your SD card. Override the file that is already there.
Go into Cubic Ninja and press L + R + X + Y and then click "Yes". Then, press Create then QR Code (make sure WiFi is on) Scan this QR Code. http://smealum.github.io/ninjhax2/JL1Xf2KFVm/q/POST5_U_12288_8203.png