So this design should work, it has worked on my server but it suddenly stopped and doesn't spawn any iron golems anymore.
The zombie seems to not agro on the villagers even when i'm far away and the villagers seem not to care about the zombie even being one block away (I tested that)
And the villagers seem to sleep and work.
There are a lot of things off there. First, villager 'cells' must be at least 10 blocks from each other or they are considered to be same group. The formation of four cells around one zombie will not work well. Having two on opposite sides (each 5 blocks from zombie location) works best.
I am also not seeing any villagers in at least three of these cells.
Are you sure that all of the villagers are working?
I haven't messed around with villagers since the early versions of 1.15 so I'm not really sure how the mechanics have changed, but I have my doubts about the villagers ability to use the 2 upper workstations in each cell.
At least in some updates villagers could only use workstations at or below their legs.
Comparing scorrp10's screenshot with yours I notice that he has the villagers bobbing in water and the slab above their heads seems to be higher than your trapdoor, which probably gives them room to bob high enough to use the workstations.
Bobbing in water is what causes villager sight line to intermittently go above or below the carpet that is on the slab in front of them. Which means that they get a 'fresh scare' every time they bob up. This causes each cell to generate a golem every 30 seconds or so. When they bob down and lo longer see the zombie, they can go to sleep or work. But while in bed, villagers again comes in sight of the zombie. So they sleep for a second or two and then wake up again, which satisfies the sleeping requirement. I suspect on OPs farm, sleeping villagers will no longer see the zombie due to glass. And yeah, the side station villagers will likely be unable to work. On the design I used, each workstation is different (not just a bunch of looms). This allows me to listen to work sounds and verify that every villager is indeed working.
So this design should work, it has worked on my server but it suddenly stopped and doesn't spawn any iron golems anymore.
The zombie seems to not agro on the villagers even when i'm far away and the villagers seem not to care about the zombie even being one block away (I tested that)
And the villagers seem to sleep and work.
Ignore the piston, I thought to use it.
Pls help, I don't know why it stopped working;
When you say "my server", do you mean that you run it, so you know there aren't any settings that have been changed?
Otherwise I'd suggest asking about that.
Are you sure the zombie and villagers can see each other? Bearing in mind that mobs can't, as I understand things, see through glass.
Is the server running 1.15 something (what exactly) or snapshots?
Just testing.
Did you change server version?
There are a lot of things off there. First, villager 'cells' must be at least 10 blocks from each other or they are considered to be same group. The formation of four cells around one zombie will not work well. Having two on opposite sides (each 5 blocks from zombie location) works best.
I am also not seeing any villagers in at least three of these cells.
For whats's it worth, this one works perfectly.
Are you sure that all of the villagers are working?
I haven't messed around with villagers since the early versions of 1.15 so I'm not really sure how the mechanics have changed, but I have my doubts about the villagers ability to use the 2 upper workstations in each cell.
At least in some updates villagers could only use workstations at or below their legs.
Comparing scorrp10's screenshot with yours I notice that he has the villagers bobbing in water and the slab above their heads seems to be higher than your trapdoor, which probably gives them room to bob high enough to use the workstations.
Just testing.
Bobbing in water is what causes villager sight line to intermittently go above or below the carpet that is on the slab in front of them. Which means that they get a 'fresh scare' every time they bob up. This causes each cell to generate a golem every 30 seconds or so. When they bob down and lo longer see the zombie, they can go to sleep or work. But while in bed, villagers again comes in sight of the zombie. So they sleep for a second or two and then wake up again, which satisfies the sleeping requirement. I suspect on OPs farm, sleeping villagers will no longer see the zombie due to glass. And yeah, the side station villagers will likely be unable to work. On the design I used, each workstation is different (not just a bunch of looms). This allows me to listen to work sounds and verify that every villager is indeed working.
This is the design with full explanation.