Lerp leaning problems

Hello,

I’m trying to implement a Leaning feature to be able to have a quick pick at wall angles.

It works but the movement is not smooth, it starts very slow and finishes fast.
I’ve tried different timeline combinations but I can’t get a constant move.

Maybe I misunderstand timelines and lerp but I’ve always done it like this and it worked. I thought Lerp A was alpha0 and B was 1

What is causing this?

Thank you.