Ok I haven't slept in minecraft for ages and I never really liked the insomnia addition with phantoms. However I find myself having to always set the doinsomnia gamerule back to false every time I switch from survival to creative and back to survival. It seems to forget that I have manually set it to false and it automatically switches back to default being true.

Steps to reproduce:

Ensure that your player has not slept in ages

type /gamerule doinsomnia false and press enter

switch to creative by /gamemode c

start building or mining for a game day

switch back to survival by /gamemode s

eventually sometimes instantaneous the phantoms spawn and start attacking