After adding a few more mods today to my Forge instance and then trying to run it on a dedicated server, I came across the following error when my client attempts to connect to the server:
Connection Lost
Internal Exception: io.netty.handler.codec.DecoderException:
java.io.IOException: Packet was larger than I expected, found 65536 bytes extra whilst reading packet 63
I tried running the new mods alone in their own instance with no issues. Then I went about troubleshooting by adding each mod individually until the exception would start occurring. When I thought I found the mod that causes the error, I would try it alone then slowly start adding mods alongside it until it would be a new mod that caused the error that had been working previously. I figured it could be having that number of mods installed causing the issue. And here we are.
Full Client Log: https://paste.ee/p/ex49J
Full Server Log: https://paste.ee/p/f80MV
No crashes. Just a disconnect caused by the exception.