Not even 5kx is possible nowadays after Pragmatic releases many similar slots such as Sweet Fiest and Enhanced versions of it.
Something is changed on such medium volatile slots so gamblers can't pass some multi levels, IMHO.
It’s a different story with old slots and also the gamblers in youtube getting max wins many times and being that lucky is kind of suspicious to me.
One more thing is switching between slots quickly after losing which many gamblers do, my conclusion after i experienced that is a very bad thing. Better to stick in one slot to boost your chance of winning big if you are lucky enough. Just my two cents