Premiere Cutting Off Part of Animated Text

I'm making a sort of 'slot machine' scroll of the alphabet. It's for a 1920x1080 video, so the type is pretty large. Everything seemed to be going well; I was using the 'Distort>Transform' effect for movement so I can add a simple motion blur.

The problem I'm having is at the very end of the scroll, it's almost like a mask starts to cover my letters, cutting almost half of each away.

Here's a screen to help with my bad explanation. The scroll only goes through the letter 'M', fyi. I've missed something, but HOURS in, I simply can't get this to stop. What am I doing wrong? Thanks!