I would not be surprised at all if it's vibe coded. I have seen exactly the same thing myself.

I gave instruction to Claude to add a toggle button to a website where the value needs to be stored in local storage.

It is a very straightforward change. Just follow exactly how it is done for a different boolean setting and you are set. An intern can do that on the first day of their job.

Everything is done properly except that on page load, the stored setting is not read.

Which can be easily discovered if the author, with or without AI tools, has a test or manually goes through the entire workflow just once. I discovered the problem myself and fixed it.

Setting all of that aside -- even if this is not AI coded, at the least it shows the site owner doesn't have the basic care for its visitors to go through this important workflow to check if everything works properly.