Chicken Cookerator Not Working

I thought before I message the devs directly, I'd post here and see if anyone has any idea what could be the issue here.

So, I built an automatic chicken cookerator 9,000, but it's not working. The chickens are laying eggs and eggs are getting dispensed no problem, but when the babies grow up and getting incinerated, they're not dropping any items.

I've already checked that my res settings allow for both chicken and adult mobs to take damage, and that item dropping is enabled (even though item dropping should be player only), yet the chickens are still not dropping anything.

Now, I can't tell if the items are just not dropping at all, or of they're being incinerated by the lava, but regardless which problem it is, something is not working properly.

This is located at my smp7 socrlax24-3 res.

I just mocked one up. I put a Lava Bucket in a Dispenser and let several Chickens grow into adults before I killed them. No drops for me either. I threw some Dirt blocks in from the top and oddly they went into the Hopper below the Lava unharmed.

It may have to do with items floating. There are also some drops you do not get unless a player kills the mob, like Spider Eyes, so something may have changed in respect to Chicken drops and Player interaction.

Another observation: I am currently in the Wild at a spot I've cleared in a Jungle Biome. During the time I waited for the Chickens to grow up, not a single mob spawned. Usually I would expect a few Ocelots at least. There is possibly something bigger going on like pushing entity limits.

Chickens should drop chicken and feathers regardless of how they're killed, and the item should drop at their feet. I'm wondering if the items are, for some reason, dropping higher up in the air and getting incinerated... or just not dropping at all... It's hard to tell. Also, I'm doing this in my res, so I can only guess that there is some sort of capping on passive mobs in the wild to prevent lag? Your issue with passive mob spawning may also be related to the absolutely bizarre hostile mob spawning I've experienced in the wild, but I don't think it's related to the problem I'm having in my res.

My guess is that this is happening because hoppers on EMC are slowed down, so the drops get destroyed before they can get picked up. The only thing I can think of to fix this is to either replace the hopper with a hopper minecart (preferably inside the slab), or if that doesn't work, try replacing the slab with a daylight sensor.

Thank you everyone for the suggestions! I will try them out and see what happens.

Update, hopper minecart worked!!! Tho I probably didn't do it like you guys were expecting hahaha

Update 2: ..... hopper minecart setup has completely stopped working.

You might be able to work around the problem with a design like this one, which briefly dispenses then retrieves the Lava before the drops are produced.