Editing Audio - export has artifacts, internal tools tricky

I'm trying to fix my video audio track. I did an export/audacity edit/import once to bump the video's volume (it was noisy/unclear bumping volume in PE, needed a noise reduction), imported & replaced audio, edited my clips so now I have a totally different track without original timestamps (which I'd love to find), exported the new WAV, and there are artifacts in it that aren't in PE. I'm having trouble cleanly bumping volume of words/phrases in PE. If I only bump certain words/phrases in Audacity because of the artifacts, it will be hard to sync to the timeline. What's an editor to do? Using Win10 64 bit PE 2020. TIA.