Sorry, your right, mhdpHdGbkoTXCfkZZQhJUgQrFiTytwB5gu sent, but why the remaining balance went to mknda3aU9LH4BAL2eqeegQRnShhQawoUWo instead of going back to mhdpHdGbkoTXCfkZZQhJUgQrFiTytwB5gu ?
you have to learn how hd wallets work. mycelium hd wallet gives a new address after every transaction. it is same in your case with bitoin qt.