nightsky shows in daytime altough glitchy

i found this gamebreaking bug when i logged into minecraft today wich renders minecraft unplayable

a black line appears just above the ground wich i have inestigated and understood that it is the nightsky. the glitch flickkers from time to time and can sometimes dissapear this is not supposed to happen i asume and hope you find a way to fix it
there is no real way to reproduce the problem since i do not know how it got there i did norhing before logging in to a new world

i have flown a bit up in creative to show that it is the nightsky with the moon while also showing clouds and the sun