textarea does not have a value attribute; so you better use the .text() function
$("#id").text(newValue);
Update: Well, I had this problem once in my old project, but after switching to .text (), it works (got a solution from here ). I know that .val could also be applied, but if you encounter such problems (this may be due to the compatibility of your browser, jquery version ...), and you are sure that your selector code is correct, then select either path (val or text)
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