Whats the problem

The map is an iron golem farm. When the villagers are scared by zombie, they totally spawn 4 iron golems at the same time. It does work in 1.19.2 and up. However, the villagers only spawn 2 or less iron golem when they are scared in 1.21.3 and up.

The Bug

Here is the link of the video of running this iron golem farm in vanilla environment (Includes 1.19.2, 1.21.1, 1.21.3 and 1.21.4)

The link: https://drive.google.com/file/d/1xQaZZuF8KHxZavkjtcvnkT-MXCi7YsoN/view?usp=sharing

In the video, there is no problem in 1.19.2 and 1.21.1.

In 1.21.3 and 1.21.4, I respawn all the villagers to see if it is MC-277889. Unfortunately, it isn't.

My Thought

(There is a redstone clock, which is about 35.2s)

I think it is because the cooldown time of spawning iron golems is abnormal. Sometimes, when I run the clock one more time, the villagers can spawn 4 iron golems at the same time. Therefore, I guess there are some problems of the cooldown time of spawning iron golems.