Maybe that helps:
jacktrip -S --loopback
mThreadPool default maxThreadCount = 2
mThreadPool maxThreadCount previously set to 32
JackTrip HUB SERVER: UDP Base Port set to 61002
JackTrip HUB SERVER: Waiting for client connections...
JackTrip HUB SERVER: Hub auto audio patch setting = 0 (server-to-clients)
=======================================================
JackTrip HUB SERVER: Client Connection Received!
JackTrip HUB SERVER: Client Connect Received from Address : ::ffff:84.175.232.149
JackTrip HUB SERVER: Reading UDP port from Client...
JackTrip HUB SERVER: Client UDP Port is = 4464
JackTrip HUB SERVER: Sending Final UDP Port to Client: 61002
Writing port: 61002
JackTrip HUB SERVER: Client TCP Connection Closed!
JackTrip HUB SERVER: Starting JackTripWorker...
Segmentation fault (core dumped)