I was in my Solo Survival World and had a Wandering trader next to one of my structures, when I took of with my Elytra and flew over to another structure of mine, the wandering trader appeared to be already there. I think the screenshots showcase what was happening quite well.

At first I even thought I had two wandering traders at once, maybe they even were, I just couldnt be in both places at once. Felt like some SCP spooky stuff right there.