Native search is working on one of my blog and not on the other one. I crossed the themes to checked if the problem could come from the theme, but it is not.
I wonder why could caused that the native search does not work, but I can’t find.
Your site is running Ghost 5.2, but search wasn’t released until 5.3 - you’ll need to update for it to work.
You also have a JS error on the page from your plausible script, which can also interfere with other JS sometimes, just in case it still doesn’t work after upgrading!
As for plausible, I do not understand why an error as I just copy pasted the script in the header. Should I warn the Plausible team of something going wrong ?
If you need help with updating Ghost then the best course of action is to raise your own topic in developer help and fill out the template with as much detail as possible.