New world created in 1.14-PRE5. The day and night cycle is taking longer than expected.

With the sun setting I could see it move below a wall, then jerk back up a little bit, with a sudden increase in brightness. It then continued to move down, and repeated.

What I expected to happen was...:
The sun should set smoothly

What actually happened was...:
Its a cycle of a few seconds, seen best against a wall acting as your horizon. The sun will set a few degrees, then suddenly jumps up few degrees, and then continues to set. It rises less than it set so it does eventually set, but it takes more time.

Steps to Reproduce:
1. Build a walled compound - I had farmer villagers if that is relevant
2. wait for sun to set
3. use the top of the wall to watch its movement