Yes, I have the same problem. I ordered 4. Two of the tubes work for me, but the other two are clogged and the package they were in was full of white plastic powder (which is what I assume is doing the clogging).
Also the End pieces are extremely fragile and some even arrived broken.
So even if half of my tubes are in working order, I do not foresee this product to be very durable. It´s just a question of time until the little holders inside the End pieces break off. Maybe a different material would help?