This is a standard Iron farm built just as directions and it works great in 1.14.4. This shouldn't happen.
This Golem spawned somehow either on the beds or on the slab ring around the beds. I first saw him on the ring and then he jumped down to the bed. This is the second time this has happened but the first time I was able to pillar up and push him off the ring before he got down to the beds.
Only thing I can think of is to remove the center cauldren so he will walk toward the zombie and fall but how can I prevent reoccuring?
I removed the center cauldren and Golem did not leave. instead, the villagers ran over the edge and died in the lava. I had to actually remove all three beds before he fell and in falling he wiped out my zombie also.
I was wondering how to shut off the farm, now I don't need to, I need to rebuild itt instead.
Still need to know how to prevent this. Think I'll try another ring of slabs above the current one around the beds in the rebuild.