If you type " /gamerules doDaylightCycle False " then type " /time set day "
(and only " /time set day " will trigger the bug") the sun will move up a little bit, then move back, move up a little bit then warp back. Strangely when i tried it with other ways such as Night,14000, 200 etc. Nothing like the one with the " / time set day " glitch appeared, also it has to be /gamerule doDaylightCycle then /time set day in that order, otherwise it doesn't occur. I have tested this multiple times.As far as i know, it occurs in singleplayer, although i am unsure about multiplayer.