When I entered my usual survival singleplayer world for the first time on version 1.20 pre-relase 1 I noticed that the sun's texture was changed to zombie's skin texture. I checked if I have any texture pack other than "Deafult" but the answer was negative. I also quit and join the world and restarted minecraft but nothing changed. The "sun" (if I can call it like that) is moving as usual from the sunrise to the sunset. I waited for night and checked if the moon texture was fine, and the answer was positive. I slept overnight and the sun was just the same texture as the previous day. I don't know what happened and what to do with it.

Update: I restarted minecraft one more time and sun's texture went back to normal.