PSTN can't hold

[nikohpng]

Describe the bug
I call out number, but when pstn number hold, fs will give 500。like this

Package version or git hash

• FS Version [1.10.7]
• sofia-sip [1.13.7]

FS debug log

2025-01-26 16:36:27.025564 96.07% [DEBUG] switch_ivr_bridge.c:912 BRIDGE THREAD DONE [sofia/csgw/jjjj]
2025-01-26 16:36:27.025564 96.07% [NOTICE] switch_ivr_bridge.c:927 Hangup sofia/csbc/[email protected] [CS_EXECUTE] [NORMAL_CLEARING]
2025-01-26 16:36:27.025564 96.07% [DEBUG] switch_core_state_machine.c:650 (sofia/csgw/jjjj) State EXCHANGE_MEDIA going to sleep
2025-01-26 16:36:27.025564 96.07% [DEBUG] switch_core_state_machine.c:581 (sofia/csgw/jjjj) Running State Change CS_HANGUP (Cur 2 Tot 88)
2025-01-26 16:36:27.025564 96.07% [DEBUG] switch_core_state_machine.c:844 (sofia/csgw/jjjj) Callstate Change UNHELD -> HANGUP
2025-01-26 16:36:27.025564 96.07% [DEBUG] switch_core_state_machine.c:846 (sofia/csgw/jjjj) State HANGUP
2025-01-26 16:36:27.025564 96.07% [DEBUG] mod_sofia.c:473 Channel sofia/csgw/jjjjhanging up, cause: NORMAL_UNSPECIFIED
2025-01-26 16:36:27.025564 96.07% [DEBUG] switch_core_state_machine.c:59 sofia/csgw/jjjjStandard HANGUP, cause: NORMAL_UNSPECIFIED

ps: this is hangup cause

Trace logs

nta.c:6882 incoming_reply() nta: sent 200 OK for OPTIONS (10)
nua_stack.c:599 nua_stack_signal() nua(0x7f3e340140a0): recv signal r_destroy
nta.c:4546 nta_leg_destroy() nta_leg_destroy((nil))
soa.c:356 soa_destroy() soa_destroy(static::0x7f3e34025e70) called
nua_stack.c:599 nua_stack_signal() nua(0x7f3e340140a0): recv signal r_handle_unref
nua_stack.c:599 nua_stack_signal() nua((nil)): recv signal r_unref
nta.c:9235 outgoing_timer_dk() nta: timer K fired, terminate PRACK (94386491)
nta.c:8907 outgoing_reclaim_queued() outgoing_reclaim_all((nil), (nil), 0x7f3e59650b30)
nta.c:9054 _nta_outgoing_timer() nta_outgoing_timer: 0/0 resent, 0/1 tout, 1/4 term, 1/7 free
nta.c:7139 _nta_incoming_timer() nta: sending final response failed, timeout 100 response
nua_session.c:2611 process_ack_or_cancel() nua: process_ack_or_cancel: entering
nua_stack.c:301 nua_stack_event() nua(0x7f3e3c018670): event i_error 408 ACK Timeout
nua_params.c:484 nua_stack_set_params() nua: nua_stack_set_params: entering
soa.c:1784 soa_terminate() soa_terminate(static::0x7f3e34038a30) called
soa.c:1302 soa_init_offer_answer() soa_init_offer_answer(static::0x7f3e34038a30) called
nua_stack.c:389 nua_application_event() nua: nua_application_event: entering
nua.c:1164 nua_handle_unref_user() nua nua_handle_unref_user(0x7f3e3c018670): entering
nua_stack.c:559 nua_signal() nua(0x7f3e3c018670): sent signal r_handle_unref
nua.c:1157 nua_unref_user() nua: nua_unref_user: entering
nua_stack.c:559 nua_signal() nua((nil)): sent signal r_unref
nta.c:2708 nta_tpn_by_url() nta: selecting scheme sip
tport.c:3286 tport_tsend() tport_tsend(0x7f3e340042c0) tpn = UDP/xxx:33141
tport.c:4075 tport_resolve() tport_resolve addrinfo = xxxx6:33141
tport.c:4709 tport_by_addrinfo() tport_by_addrinfo(0x7f3e340042c0): not found by name UDP/xxx:33141
tport.c:3623 tport_vsend() tport_vsend(0x7f3e340042c0): 637 bytes of 637 to udp/xxxx:33141
tport.c:3521 tport_send_msg() tport_vsend returned 637
send 637 bytes to udp/[xxxx]:33141 at 16:36:27.029016:
------------------------------------------------------------------------
BYE sip:xxxx:33141;did=9f4.527e4b81 SIP/2.0
Via: SIP/2.0/UDP yyyy:16522;rport;branch=z9hG4bKZa7XXgZH8amUB
Max-Forwards: 70
From: "20087438" <sip:+zzzz@yyyy>;tag=HX2t9ap4paU8c
To: <sip:18484607402@xxxx:33141>;tag=106-202-347342
Call-ID: 72c29388-5663-123e-ee88-000c2997a3d6
CSeq: 94386497 BYE
Contact: <sip:gw+csgw6@yyyy:16522;transport=udp;gw=csgw6>
User-Agent: 192.168.1.117
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, PRACK, NOTIFY
Supported: 100rel, path, replaces
Reason: SIP;cause=408;text="ACK Timeout"
Content-Length: 0

ps: xxxx or yyyy is not err. it't public ip, i can't open it