Can't, not after ENT-D goes at Warp 10 and travels to another galaxy. Or original Enterprise travels outside the galaxy a couple of times, or to the galaxy's core a couple of times without issue.2. Explain the plot of Voyager.
Voyager's plot has been problematic long, long, before Discovery.
Mudd went a bit mad. Time Travel will do that. Mudd forgetting about spore drive technology