Fortigate client not able to sync with chrony when using SHA symmetric key

Issue

• There is no reply from the RHEL NTP server when using a FortiGat device with SHA key.
• The authentication fails, as showed in chrony debug log:

Jun 27 13:36:12 localhost chronyd[2555001]: 2025-06-27T08:06:12Z D:socket.c:795:(log_message) Received message from <clientIP>:123 to <serverIP> fd=5 len=72 if=2 tss=K
Jun 27 13:36:12 localhost chronyd[2555001]: 2025-06-27T08:06:12Z D:ntp_io.c:460:(process_message) Updated RX timestamp delay=0.000062026 tss=1
Jun 27 13:36:12 localhost chronyd[2555001]: 2025-06-27T08:06:12Z D:clientlog.c:574:(CLG_LogServiceAccess) service 0 hits 96965 rate -16 trate -128 tokens 0
Jun 27 13:36:12 localhost chronyd[2555001]: 2025-06-27T08:06:12Z D:ntp_core.c:2707:(NCR_ProcessRxUnknown) NTP packet failed auth mode=1 kod=0