Issue should be fixed. The dev accidentally had an exit box near where enemies come in on the lower right and that would trigger like they reached the end of the level. How I fixed the game initially was to create a copy of it and have those enemies enter in a different path, but then he updated the game, so I went back to his build where the enemies came in on that path.

I think what happened was the game update package had the updated Construct 3 file of the game, but still the old HTML, so I just opened up Construct 3, did another export of the game from Construct, and then uploaded that package over the top of the old one.

You may need to hit Contro+F5 (or a similar key combo depending on your OS and web browser) to hard refresh the tab with the game in it to reload with the newest version of the game files.