Orbits devolve over time...

[JMBuilder]

I'm trying to recreate the Lylat System from the StarFox games (Spica acting as "Lylat Prime"). I have a good number of planets orbiting over 100 AU away from Spica, all of their orbits at least 20 AU away from each other. If I speed up time and give it about 50,000 years, the planets start to go a bit crazy with their orbits, becoming more and more eccentric and elliptical over time.

I'm especially worried about this since Lylat is a multiple star system (a red dwarf and a yellow dwarf would orbit a blue giant), which would probably make things ten times worse...

My only thought is that maybe the planets are going slow enough around Spica to affect each other's orbits. Is there something I'm missing?

EDIT: I have the same issue with the stars. I have a blue giant with a red dwarf orbiting about 500 AU away from it. A yellow dwarf orbits tens of thousands of AU around the barycenter. This is only stable for a few orbits before the red dwarf goes eccentric and elliptical and is eventually thrown out of the system. I guess you could say I don't understand the gravity of the situation.

EDIT AGAIN: I just tested identical stars in a perfectly circular binary orbit. Same thing. When you accelerate time and reach only a few years, the two stars eventually fling past each other and go their separate ways. Is this a feature or a bug?

EDIT ONCE AGAIN: I'm convinced that the issue is time acceleration. I just looked through the in-game tutorials. Seems like accelerating fast just breaks everything, which can get annoying when you have objects orbiting close and fast as well as objects several thousand AU out orbiting REALLY slow.