not a single flake anymore

I've ordered plants often here and was so far also always impressed by the beautiful plants. Unfortunately, not a single flake of duckweed is now nowhere to be found in the aquarium after 2 weeks. I would have bought this Duckweed on the advice of a friend out, since they are usually very robust and add up quickly by itself. In my aquarium the first leaves are already on the 2nd day dropped to the ground and just now no longer there. What a pity, has initially looked great.