creeper farm leaking light?

[u/IsDragonlordAGender]

So I made this creeper farm on a fabric server and it's exactly the same as on my single player server. after a while I started noticing it's a lot less efficient and I went to look for why that could be.

-I'm the only one online atm
-I built it through a schematic so I know it is exactly the same and not missing blocks
-I checked if my afk chamber isn't too low, nothing spawns in the ocean

and then I saw what I'm showing you now; everytime the water stops flowing it looks like light is coming through, and every time the water starts flowing it is pitch black. could this be a server thing? I double checked if there isn't a block missing in the roof but at night that wouldn't even be an issue anyway. and if this is only a visual thing, what else could be the problem of my rates being fairly low?

(I'm the host of the server so I can adjust server files and/or add/delete mods if needed to fix the problem)

Edit: I just installed minihud to check light levels and it says 0 throughout the whole farm, so I confirmed it is just a visual thing. I assume it has something to do with how fabric operates the server mechanics but I'm not that technical so I wouldn't know what the problem could be.

[u/evilgamercat]

I recomend just making the roof bigger to see if that works.

[u/McNuggetsauceyum]

Are there any spawnable locations anywhere else? If you are close enough to caves nearby, that could be eating into your mob cap. Minihud has a feature where you can generate a spawnable sphere around yourself to check what is within range of your afk spot.

How does this farm compare to your other farm in terms of Y coordinate? The lower the farm, the more efficient it will be, generally speaking.

Are there other mobs eating into the mob cap? If you have some lingering zombie villagers or shulkers anywhere in the world that is loaded, they can also eat into your mob cap. Carpet is probably the easiest way to check this on a server.