Textarea box moving on click on initial page load

I think this is because of the Grammarly plugin. Once I had this kind of issue but when I turned off that plugin, I've solved it. So just check whether this works..

Like the other answers, I think it is because of your 3rd-party plugin.

As a workaround, you could try forcing the position attribute to static since I am guessing that's what's causing it to jump (the plugin may be changing the position) - Without seeing the code I don't know for sure though.