How to change value for parameter in BigQuery datatable with SQL

Question

Situation

I have a BigQuery datatable (004a-TWtweets-02) of Twitter posts (tweets).

For a given tweet_id parameter, I am trying to change the score value from .3 to .2, which will then change a sentiment2 value from positive to neutral.

Attempted solution

I'm using this BQ SQL:

UPDATE `pp-004a.004a02.004a-TWtweets-02` SET score=2 WHERE tweet_id=1525524602327379969;

Results

That worked for the score parameter, as when I search for that tweet:

SELECT * FROM `pp-004a.004a02.004a-TWtweets-02` WHERE tweet_id=1525524602327379969

I found the new score value to be '2'.

Error

However, when I try to update the calculation for the sentiment2 parameter across the entire datatable, per below …

UPDATE
 'pp-004a.004a02.004a-TWtweets-02'
SET
 sentiment2 =
 CASE
   WHEN score<=-0.3 THEN 'Negative'
   WHEN score>=0.3 THEN 'Positive'
 ELSE
 'Neutral'
END
WHERE
 TRUE

… the same tweet_id value 1525524602327379969 still has a sentiment2 value of positive, when it should be neutral based on the new score being below the positive threshold of 3.

Is there something I'm overlooking here?