I found the problem! Just had to post on here first haha. I was on a "Take" and not the main workspace so apparently it does not show up when you're on a selected take.

This seems to be a new bug with R26 for me. In R25 it worked fine. I can't get the soundwave to show up, even though I hear the sound. I've tried clicking, Edit > Show soundwave. I've tried dragging the null into the timeline but it won't show up in there unless I add a keyframe somewhere. I've tried unchecking Filter > Animated only.

I also can't find the audio track on the null to change it later on, as it does not show up in the attribute manager. I don't know if I'm doing something wrong, but I didn't have any of these problems in R25 using the same methods.