What happened to my planet?

I had a solar system on Starchitect. The parent star was a F0 star, and had four planets: two Medium (Earth-sized) rocky planets and two Small (Saturn-sized) gas giants. One terrestrial planet was at 0.03 AU away from the star, while the other terrestrial was 0.1 AU away. The two gas giants orbited at 0.44 and 1.07 AU away.

At the age of 2.74 billion years, the star had its helium flash, destroying the 0.44 AU gas giant and the 0.1 AU rocky planet. All other planets survived. That was strange as the innermost planet (0.03 AU terrestrial) survived the flash, while the middle two planets were destroyed. Then, 10 minutes (10 million years) later, the innermost planet was destroyed. Finally, the outermost planet was destroyed at 2.8 billion years as the F0 star entered its red giant stage. You can view the system, nicknamed "HOT HOT HOT" (Lol, that was my first F0 system), on my Starchitect profile (IGN WarpPrime).

Why are the other planets being "roasted" first instead of my innermost planets? Is this a bug?