I have the same problem when using my phone. I get so frustrated! I find if I clap, leave the piece, go back to the piece and see that my claps are gone, I can clap again, leave, go back to the piece and the claps are there. Sometimes I have to do it multiple times but USUALLY it works eventually. However, there are some pieces where the claps never stay. These are often excellent posts that should have hundreds of claps but have none. Obviously, people are clapping but no one’s claps are registering. James Finn has been communicating with Medium Staff about the problem and supposedly they are working on it. However, the excellent work here will never recover lost claps. So disappointing!