Transient simulation running better with larger timestep
 

I am simulating combustion with the premixed model, had the timestep on 0,001 and the residuals where barely converging, energy was around 1e-4, continuity 1e+1. Then I changed the timestep to 0,005 and now the residuals are converging more?! How does that work? I changed nothing else. Does Fluent simplify the calculations for larger timesteps or something?
Thanks!

maybe some sort of turbulence motions are averaged?

this is what I guess

That could give a false indication of convergence right? The larger timesteps are not as trustworthy as smaller, harder to converge timesteps.