Automated Kiln using Flame-Grilled Wopper disappears completed items.

Bug Description

I have a basic kiln setup going using a flame grilled wopper, in addition to the usual hopper and chests. The kiln accepts inputs from a chest like normal, and cooks them like normal, with the flame grilled wopper underneath, but the completed items fail to gather in the chest below the flame-grilled wopper. The completed items are being disappeared rather than gathering in the output chest.

I see this was an issue years ago that was at one point resolved, but I seem to be having an exact replica of the issue described here: https://github.com/DarkPacks/SevTech-Ages/issues/689

Did this behavior use to work in the previous version?

This is my first time playing Sevtech Ages.

Steps to Reproduce (for bugs)

Set up a kiln (K) with hopper (H), primal chests (C), and flame-grilled wopper (F) like so

C H K F C

Put items to be fired in the kiln into the chest at the top. They will feed into the kiln but then be disappeared afterwards rather than gathering in the output chest.

Logs

Client/Server Log:
Crash Log:

Client Information

Modpack Version:3.1.7
Java Version:1.12.2
Launcher Used:Twitch
Memory Allocated:4.5 GB
Server/LAN/Single Player: MP Server
Optifine Installed:No
Shaders Enabled:No

World Information

Modpack Version world created in:
Additional Content Installed:None

DarkPacks / SevTech-Ages