I've noticed this during development as well, i think it is a bug in Green, not Anser, since Green can't even scan its own QRs (if they have assetid or amount), while they all work fine with Aqua and other wallets.

As a workaround you can send everything (including the non L-BTC assets) to the L-BTC qr that works fine with Green, since all the other QRs are just the L-BTC address with some hints to get the wallet client to automatically select the right asset and amount.