Change resistance value after starting a circuit
Change 1 of those lower 10K resistors to say 9.1K, you need to unbalance the circuit so 1 transistor preferentially trips before the others, it will change the timing of that light slightly, but will make it more reliable at start up,

with a low noise voltage source like a 9V, its possible there is not enough difference between the 3 transistors to cause a consistent start up.