Ar 234 B-2 is missing RATO boosters(Rocket-Assisted Takeoff) in custom loadouts

In the default loadouts, ar 234 b-2 has RATO boosters like picture 1.

But while using custom loadout, there are 2 “ghost slots” can’t be select to load anything, and I believe those 2 slots is for the RATO boosters, like picture 2.

And if I using custom loadout in test flight, the RATO boosters are missing, like picture 3.