I had cervical spine surgery this past May 2025 and they are much less often it seems since. The only time I get them now, and they're much milder, is when I sit or lay in the wrong position or twist my wrist or hand where it doesn't like going. Also, if I haven't had enough water and/or salt in my diet, it seems to occur then. I drink pickle juice, yellow mustard, and will next try a few grains of sea salt... Sometimes ALL of them at once. The sea salt works well for a friend but I haven't tried it yet. Try to stay hydrated and see how long you go without episode, maybe? Sounds like you've been thoroughly checked already for possible causes. Good luck!