Clipping/choppiness in playback

New user here.

I'm just trying Audition for the first time and I'm noticing bad clipping happening on a certain phrase, along with some variable choppiness -- meaning, where the choppiness happens changes its location -- in playbacks.

The copy I'm reading: "Get a smooth, clean shave every time with Harry's razors. Our precision-engineered blades are designed to glide smoothly across your skin, while our ergonomic handles provide a comfortable grip."

I tried reading that three times in a row in the same recording. The first take had clipping on "engineered" (it sounds like "our precision-engi-- blades", missing that entire chunk of one word). There's also choppiness happening throughout.

In the second take there's no initial choppiness at all, but the recording cuts out at a different point, sounding like "precis-- engineered blades".

The third take has a weird hiccup before "razors" (an loud click not from my recording that I know of), and it cuts out at a completely different point. Here it sounds like "are desi-- to glide smoothly"and then "provide a comfor--ble grip".

As I know gear matters, I'm using a Shure SM58 mic, a UR12 interface, and plugging into a Windows 10 computer running Audition.

So some questions:

- Why would the playback have sporadic, moving issues despite output choice (it does the same thing with both headphones and when played through laptop speakers)?

- Why the clipping in different parts of the same copy on three takes? If anything, my waveform is small (an issue I'm noticing with this dynamic mic in various recording software), so it's not like I'm peaking out levels, it's literally just skipping recording those seemingly random bits entirely.

- And, of course, can you recommend some quick solutions to these issues?

Thanks.