Something must reason the server to not process ticks effectively. The ServerHangWatchdog, as you may have speculated, watches the server for hangs, and murders it after 60s without ticking I'll attempt and investiage the issue, on the off chance that I can duplicate it. Would you be able to please take a stab at beginning the Forge server once more, and have the main association with it be a vanilla customer? Just to test on the off chance that you can duplicate the issue neatly.