Continuing the discussion from Warcraft III: Reforged Patch Notes - Version 2.0.3:
So this is not yet fixed properly, tested it out in video for you, does seem to behave when you retry the same route but the fact that it bugs out initially should never happen.
Video.
https://drive.google.com/file/d/1kXfuhPMnWzraXXZ0xYcwjgXlXSXn7Mpa/view?usp=sharing
Also check out these 3 bugs ive reported:
Editor - Please add these features to Map Options
Editor - Please Fix Starfall and Monsoon once and for all
Editor - Please fix Techtree Requirements once and for all