why does this work?

just time out
as i said, did everythinig i could to shortened it.
i believe i wasnt expected to do super advanced math calculation as a basic kata and as a programming challange and not a math question.
for finding the next prime i only checked previous primes and not all numbers until the root
i used a generator function to calculate only whats necessary

i tried to make it faster as much as i could but its still taking over 12 secs
created a list of primes and every new num checked on the list rather than range, checking only odd numbers
what can i do?
(python)