Test with Symba
I Gabriele, I hope everything is well, I did some more testing with Symba and all the comparison with RK looks ok
Also I have checked the time step distribution with the dt_logger introduced by @alainm
on the test I did (1 or 2 planets / small and big planet masses) the dt has very small variations at the beginning then tipically remains constant ,
from my point of view we are ok with Symba but I wait for your more carefull test about resonace captures