BUG REPORT? - Solo Ops weapon focusing broken

Hoping to farm "Resounding", the strand Fusion under solo ops. I focused the weapon before starting the grind

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I've since run every Single Solo Ops on GM with S+ rating to get all bonus drops. This grind gave me over 40 pieces of loot

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Not a single Resounding.

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I either have the worst RNG of all time, or I'm missing something big here

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