Phrases Asking for Clarification

I'm not quite following.

C2

Meaning

I don't fully understand what you're saying.

Example sentences

John: So, the algorithm recalibrates based on user input.

Alice: I'm not quite following. Can you explain that again?

John: It adjusts its parameters in response to user actions.

Alice: Okay, but I still think I'm not quite following the exact mechanism.