The chunks have to be loaded, so either be within 128 blocks or put it in the Spawn Chunks.
But your main problems are:
Unless you use some complicated trickery with redstone and/or moving villagers around villages have to be at least 66 blocks apart or they merge, forming one village with the center in between.
Some or all of the villagers may be too far above or below the new center of the merged village to be counted.
By my calculations the bottom villagers would be 7 blocks below the center if all doors were counted, that's too far.
If you have at least 10 villagers in the upper level then golems should be trying to spawn but maybe not where there is room for them.
The doors between the villagers and the golem area have a roof five blocks out on both sides so they don't count as houses. The, presumed, doors on the right of the second picture may well have too much roof over them as well (all that dirt at the top right.)
Is there a villager pod on the right side of the second picture? Otherwise the doors I presume are over there will be out of range of the villagers if none of them are on that side of the potato farm. The same is true of the doors at the far right of the visible rows.
So, remove the roofs at left and right, glass is fine.
You only need one row of glass in the roofs, say right in front of the doors (not above them) in case the roofs are for lightning protection, though I think glass works for that.
Knock out one layer of doors and have at least 10 villagers by the other layer.
Stick some villagers on the right side if they aren't already there.
Keep at least one villager on either side a bit closer to the doors so you're sure that all the doors get counted, moving the wall of their enclosure in 2-3 blocks should do it (most of the time anyways).
If you want a second farm build it 70 blocks away. (66 plus a margin for error.)
70 blocks straight up is fine if you make sure the upper one dosn't shade out any doors of the lower one.
If you build the second exactly above the first you can avoid that by replacing the row of the upper farm closest to the doors with glass so the sky is visible from outside the lower doors.
I found that just having the golems fall out the bottom of the upper iron farm into a hole in the roof of the second worked fine, no chute neccesary, if you find golems on the roof, just enlarge the hole a bit.
Yea, you shouldn't just arbitrarily change things in a tutorial unless you know what you are doing. Your end result is quite a mess, and even if you had managed to get more doors and villagers working, it would not have helped. You would have gotten no more iron than the simpler tutorial design. To get more iron you need more VILLAGES, not more villagers. While having more villagers will raise the golem cap and allow more golems to spawn, it does not increase the rate at which they spawn. So in an iron farm where the golem is moved out of the village and killed, you won't get any more iron.
Back in version version 1.8 of the one true Minecraft (Java ) I built a six village iron farm with 2 stacks of 3 villages each, and I added a Redstone Jazz style pigman spawner in the middle for a little gold as well.
Villages need to be at least 65 blocks apart to prevent merging. My spacing was 68 horizontally and 70 vertically. The golems are flushed to a central lava blade kill area, while the pigmen fall to their death. All the drops are collected by hoppers and sorted into chests. This farm has survived transitions from 1.8 all the way through to the current 1.12.2 without breaking (which is more than I can say for several other farms I have in that same world).
Although I have made one major modification...
When fireworks rocket powered Elytra became a reality, I replaced the pigman spawner with a creeper spawner for gunpowder.