Some exotics have stats that are favored. Exotics that boost the efficacy of your melee (like peregrine greaves) will generally tend to roll with more strength and the same idea can be applied to other exotics with different stats. This lean takes priority over whatever your ghost has. This isn’t a bug, this is just them not explaining how the system works at all or, more likely, them not knowing how it works themself 😭