Error occurred during test: TypeError: NetworkError when attempting to fetch resource.

[alex9434]

I got the following error message when trying using https://test.voip.librepush.net/: Error occurred during test: TypeError: NetworkError when attempting to fetch resource.
My setup passes all tests from https://federationtester.matrix.org. Here is the relevant extract from turnserver.conf:

use-auth-secret
static-auth-secret=*deleted*
realm=*deleted*
external-ip=*deleted*
max-port=49407
no-tcp-relay
total-quota=1200
cert=/srv/storage/fullchain.pem
pkey=/srv/storage/privkey.pem

All other values are on default. Here is the logfile from coturn

0: (32725): INFO: System cpu num is 4
0: (32725): INFO: log file opened: /var/log/turn_32725_2024-04-15.log
0: (32725): INFO: System enable num is 4
0: (32725): INFO: Coturn Version Coturn-4.6.2 'Gorst'
0: (32725): INFO: Max number of open files/sockets allowed for this process: 4096
0: (32725): INFO: Due to the open files/sockets limitation, max supported number of TURN Sessions possible is: 2000 (approximately)
0: (32725): INFO:

==== Show him the instruments, Practical Frost: ====

0: (32725): INFO: OpenSSL compile-time version: OpenSSL 3.0.12 24 Oct 2023 (0x300000c0)
0: (32725): INFO: TLS 1.3 supported
0: (32725): INFO: DTLS 1.2 supported
0: (32725): INFO: TURN/STUN ALPN supported
0: (32725): INFO: Third-party authorization (oAuth) supported
0: (32725): INFO: GCM (AEAD) supported
0: (32725): INFO: SQLite supported, default database location is /etc/turnserver/turndb
0: (32725): INFO: Redis supported
0: (32725): INFO: PostgreSQL is not supported
0: (32725): INFO: MySQL is not supported
0: (32725): INFO: MongoDB is not supported
0: (32725): INFO: Default Net Engine version: 3 (UDP thread per CPU core)
0: (32725): INFO: Domain name:
0: (32725): INFO: Default realm: *deleted*
0: (32725): INFO: CONFIG: --no-tcp-relay: TCP relay endpoints are not allowed.
0: (32725): ERROR: CONFIG: Empty cli-password, and so telnet cli interface is disabled! Please set a non empty cli-password!
0: (32725): INFO: Certificate file found: /srv/storage/fullchain.cer
0: (32725): INFO: Private key file found: /srv/storage/priv.key
0: (32725): INFO: TLS cipher suite: ALL:!COMPLEMENTOFDEFAULT:!eNULL:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256
0: (32725): INFO: DTLS cipher suite: ALL:!COMPLEMENTOFDEFAULT:!eNULL:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256
0: (32725): WARNING: NO EXPLICIT LISTENER ADDRESS(ES) ARE CONFIGURED
0: (32725): INFO: ===========Discovering listener addresses: =========
0: (32725): INFO: Listener address to use: 127.0.0.1
0: (32725): INFO: Listener address to use: 192.168.178.177
0: (32725): INFO: Listener address to use: 172.17.0.1
0: (32725): INFO: Listener address to use: 172.18.0.1
0: (32725): INFO: Listener address to use: ::1
0: (32725): INFO: Listener address to use: *deleted*
0: (32725): INFO: Listener address to use: *deleted*
0: (32725): INFO: =====================================================
0: (32725): INFO: Total: 5 'real' addresses discovered
0: (32725): INFO: =====================================================
0: (32725): WARNING: NO EXPLICIT RELAY ADDRESS(ES) ARE CONFIGURED
0: (32725): INFO: ===========Discovering relay addresses: =============
0: (32725): INFO: Relay address to use: 192.168.178.177
0: (32725): INFO: Relay address to use: 172.17.0.1
0: (32725): INFO: Relay address to use: 172.18.0.1
0: (32725): INFO: Relay address to use: *deleted*
0: (32725): INFO: Relay address to use: *deleted*
0: (32725): INFO: =====================================================
0: (32725): INFO: Total: 5 relay addresses discovered
0: (32725): INFO: =====================================================
0: (32725): INFO: pid file created: /var/run/turnserver.pid
0: (32725): INFO: IO method: epoll (with changelist)
0: (32725): INFO: RFC5780 disabled! /NAT behavior discovery/
0: (32725): INFO: Wait for relay ports initialization...
0: (32725): INFO:   relay 192.168.178.177 initialization...
0: (32725): INFO:   relay 192.168.178.177 initialization done
0: (32725): INFO:   relay 172.17.0.1 initialization...
0: (32725): INFO:   relay 172.17.0.1 initialization done
0: (32725): INFO:   relay 172.18.0.1 initialization...
0: (32725): INFO:   relay 172.18.0.1 initialization done
0: (32725): INFO:   relay *deleted*:3927 initialization...
0: (32725): INFO:   relay *deleted*:3927 initialization done
0: (32725): INFO:   relay *deleted*:3927 initialization...
0: (32725): INFO:   relay *deleted*:3927 initialization done
0: (32725): INFO: Relay ports initialization done
0: (32725): INFO: Total General servers: 4
0: (32726): DEBUG: turn server id=0 created
0: (32727): DEBUG: turn server id=1 created
0: (32728): DEBUG: turn server id=2 created
0: (32729): DEBUG: turn server id=3 created
0: (32725): INFO: Total auth threads: 3
1: (32725): INFO: turnserver compiled without prometheus support

WebRTC with https://icetest.atec-systems.com/ shows successful TURN and TURNS connections.

Please let me know how I can debug further.