[2019] 90% reduced weight legendary effect doesn't work like other effects

For example the legendary effect Two Shot in a Pipe Weapon, I can mod/change receiver, barrel, etc and the effect continues to work, same for other legendary effects. But 90% reduced weight has a bug, if I mod the weapon the legendary effect doesn't work for the changed parts, it should always work just like other legendary effects.

Edit: just think about other effects, for example +40% bashing dmg, you can change stock, even remove it entirely and the effect still applies.

All other effects continue working like they should, 90% reduced weight is bugged.

Edit 1: notable effects that continue working (they all do except for WR) just for you to see:

• Anti-armor, change magazine, receiver, etc it still works
• Quadruple, change magazine and it works for all of them
• 40% swing speed, change mods and therefore weight of the weapon and it works
• 40% more power attack, same
• Reflect 50% while blocking, same
• 25% increase fire rate, change receiver, the percentage always applies
• 10% increase while aiming, change sights, percentage still applies
• Bullets explode, change receiver bonus still applies
• 15% faster reload, change magazines bonus applies
• Move faster while aiming, change weapon weight, still applies

They ALL still work, 90% WR doesn’t.