There are a number of guidelines for hyphenation in English. one of them is:
Don't hyphenate after a short vowel.
Following this guideline you get: If it's pronounced /kɪnɛtɪk/, hyphenate after the 'n'; if it's pronounced /kənɛtɪk/, hyphenate after the 'i'. I suspect this is the reason for the difference between the two dictionaries.
One side comment: the actual hyphenations given by Merriam-Webster don't follow a single set of rules: they involve judgment calls where two of these rules conflict (e.g. rational) and some cases where historical hyphenations no longer make sense (fair-y and prai-rie seem to be hyphenated the way they are because they didn't rhyme 100 years ago).
And as a final side comment: I am sure that both pronunciations are used by Americans.