Maybe you can reach out to me (zwarf@mail.de) and explain directly how the above error happend. I can not follow when this exactly happens.
Regarding the “wrong” times: What I found out during writing my calculations/creating the formulas and checking then with other data, the “problem” is a matter of taste and not wrong or right.
My definition of sunset is when the center of the sun is at 0° elevation. Some programs define set when the upper point of the sun “disk” is at 0°. However, always keep in mind that this is never the “real” sunset because nearly no program takes your environment into account for example if you are in a valley it can happen that you never see the sun however the program says you have a sunrise.
Maybe compare it with reality on a flat field for example and give me some feedback how you experience it if you like.
I already try to find a solution to calculate the “real” sunrise and sunset (see my issue on GitLab).