hi respect for fiddler, i am from russia
subj, yes win xp base not support tls 1.2, only third party libraries supoport tls 1.2 on win xp (curl, openssl)
log from fiddler
HTTP/1.1 200 Connection Established
FiddlerGateway: Direct
StartTime: 07:57:56.679
Connection: close
fiddler.network.https> HTTPS handshake to 38.is-mis.ru (for #47) failed. System.IO.IOException Неожиданный EOF или 0 байт из транспортного потока.