ScrollRect.LateUpdate is undoing my attempts to manually scroll it

Here's my situation: I have an object with a ScrollView, which holds an object called OutputText that has a Text component and a ContentSizeFitter. I periodically add text to this Text component, the ContentSizeFitter should make the object larger to accommodate all the text, and then I can scroll it with an associated scroll bar. This all works perfectly.

What I also do, is attempt to scroll the ScrollView to the bottom after I add some text. To do this, I grab the scrollRect, and set...

ScrollRect.LateUpdate is undoing my attempts to manually scroll it