If you already have opened the link to the game before, most probably the browser holds a copy of the files locally, so when you update new files on the site, sometimes the browser doesn’t update the files of the playtest and then you get problems.
Most times you can solve those issues with a hard refresh (usually control + F5, it depends on the browser I guess, I don’t know them all) You can also check the scenes to see if what you’re looking at is the last ones you uploaded.