ARC Won't Connect: VF DE Cable and FRITZ!Box 6660

Same here, even though I updated to ROCK os 258…

Vodafone Germany, Cable (the famous IPv6 issue)
Fritz Box 6660

{
“ipv6_connectivity”: {“status”:“NetworkError”,“status_code”:504,“error”:“error: Error: ETIMEDOUT, response code: undefined, body: undefined connected? undefined”},
“ipv4_connectivity”: {“status”:“NetworkError”,“status_code”:504,“error”:“error: Error: ETIMEDOUT, response code: undefined, body: undefined connected? undefined”},
“external_ip”: {“actual_external_ip”:“88.hhh.iii.jjj”,“actual_external_ipv6”:“2a02:aaa:bbb:ccc:ddd:eee:fff:ggg”,“router_external_ip”:“null”},
“status”: “status”: MultipleNatFound
,
“natpmp_autoconfig”: {“status”:“NotFound”},
“upnp_autoconfig”: {“server_ip”:“192.168.178.1”,“found_upnp”:true}
}