In my iron farm golems aren't spawning not just golems but also the cats have stopped spawning 

This started happening recently 

I made my iron farm which contains the following:

1) 20 villagers each linked to a bed and a job block 

2) a automatic killing chamber which uses magma blocks to kill and water to flow the golems to magma blocks 

3) 3 floors each being in the spawning range of iron golem they have flowing water on it to make iron golem flow down to ground and go to killing chamber

4) torches in the farm layout 

5) all floors are 4 block tall 

6) all villagers have access to their beds and job blocks 

until a while ago when i was building the iron farm golems and cats were spawning and they did so until i saved the world 

But when i opened it back they stopped 

I checked on the villagers, each floor and killing chamber they are the same as they were before i saved the world so basically the farm is still the same but golems amd cats aren't spawning 

The gamemode is in Survival and difficulty is set to normal 

All the settings are default 

The screenshots are taken in creative to be able to access the positions easily in a copied world

link to the world 

https://drive.google.com/file/d/1SbjGIDLTOpAZFhvFCMcuJf32yqTERoGu/view?usp=drivesdk

Here are the screenshots