After the three starting players joined the server we received issues with new people joining, where it disconnects them and says "Internal Exception: java.net.SocketException: Connection reset".
They appear to connect to the server, then move around and try interacting with blocks, items, etc until they are disconnected from the server and receive the aforementioned "Connection Lost" screen.
Below I have posted the server log files and two of the external players' log files when they tried joining the server numerous times.
Player 1 Logs
Player 2 Logs
Server Logs
I'm not sure why it continues to disconnect them, whether it's a mod confliction, clientside internet issue, or serverside issue overall, but we've attempted troubleshooting to no avail. Any help would be much appreciated