I need help figuring out my GB12 speed team inconsistency

This is 2 clips from my GB12 speed team. The first one has Prilea missing defense break on S3, and Julia/Mephisto consistently don’t have an issue killing the wave after.

In the second clip though, when Prilea uses S1, she misses the defense break on the first hit and lands it on the second. By all means, Julie/Mephisto should be better set up here, no? I can’t put together what’s causing Mephisto to do less damage.

Pls help me out guys, I’ve been sitting on this and am totally lost 🙏🏼