Finality buff from Duality Quarterstaff disappear on weapon swap

Hi,

I'm playing a Werewolf Martial Artist Monk with Martial Adept and Martial Master allocated. I wanted to use the Duality quarterstaff in my second weapon set to proc Finality with Tempest Bell before switching to Shred in Werewolf form. Since Finality buffs Final Strikes and Shred uses that term, I expected the buff to persist through a weapon swap and remain usable while shapeshifted.

I can proc and use Finality without any issues while using a quarterstaff (tested with Tempest Flurry), but as soon as I swap weapons, the buff disappears and does not appear to affect Shred in any visible way. This does not happen with the Guard buff from Duality, which persists through weapon swaps without any problems.

Is this intended behavior for the Finality buff, or is it an oversight?

Thank you.