I play nightfae on my mage
I also have ss/video proof of seed being healed and taking way more than the flat damage
You’re only saying you’re seeing it just die with the link but not extra healing or something? I also think it’s likely you could just be fighting a spec that can 1 tap the seed (Ret/boomkin if they have burst available still).
Person can also rez and die if the seed dies right after they rez, there’s a small window for this too