@FunkyHut I can only guess the frustration you are feeling.
There have been plenty of reports of stuttering since the game launched and there have also been some success stories about ‘fixes’ that work- however there seems to be no one size fits all for these ‘fixes’.
I hope that Zendesk respond to your ticket soon. In the meantime you may find some of the discussion in this thread to be helpful: Solution for Stutters & Pauses