And yes, sorry for the mediocre description of graph. Made it in a rush.

@SeanE.Lake I obtained equations of motion using Lagrangian, I was using rigid bodies, constant rod length, point mass of bob and rods without mass, no friction etc. so idealised mathematical model.

I will try increasing runtime of simulation. I made this post because I am scared that calling the behaviour chaotic with such low lyapunov exponent might be seen as a critical mistake. P.S. I meant the lyapunov exponent at higher initial energy positions. I know that after $\pi$ the values are mirrored.

hyperphysics.phy-astr.gsu.edu/hbase/pend.html#c3

Before I started working on double pendulum I did some simulations for single pendulum and there I had equation for Theta with only one variable, time. I was able to write a loop with t += 0.05 and everything worked.