The Lerp node will clamp input to between 0 and 1, meaning it only use values from 0 to 1. You should try to divide the alpha value with the total timeline length, then feed the result to the Lerp node.
The Lerp node will clamp input to between 0 and 1, meaning it only use values from 0 to 1. You should try to divide the alpha value with the total timeline length, then feed the result to the Lerp node.