ARC connection not working on my QNAP

QNAP TS873
Router ASKEY RTF8115VW
Ethernet. I don’t use VPN
95621 tracks

ARC doesn’t work on my QNAP.
I have manually opened port 55002 on my router
Can you help me?
Thank you very much.

{
“connectivity”: {“status”:“NetworkError”,“status_code”:504,“error”:“error: Error: ETIMEDOUT, response code: undefined, body: undefined connected? undefined”},
“external_ip”: {“actual_external_ip”:“83.aaa.bbb.ccc”,“router_external_ip”:“null”},
“natpmp_autoconfig”: {“status”:“NotFound”},
“upnp_autoconfig”: {“server_ip”:“192.168.1.1”,“found_upnp”:true,“error”:“Did not find UPnP service with WANIPConnection on network”}
}