Alignment gone wild! Ghost in the machine!

I was just starting to experiment with the previous version of Blocs when v3 came out. So I’m a double-rookie. I’m learning, little by little, but there are a few things I find extremely annoying.

For instance, if I attempt to edit some text, the entire paragraph jumps back and forth from left alignment to center alignment. I have a hard time getting my cursor on the word that needs changing. What’s with this twitchy behavior?