Have you tried from another device to narrow it down to the windows machine or the router?
Pingtools is a fantastic Android app for doing 1001 network related tasks (ping/tracert/subnet scan/whois/etc). Worth a try if you have an Android phone.
traceroute to Google.com (2a00:1450:4009:801::200e), 30 hops max
Hop 1:
From broadband.bt.com (2a00:23c4:2bc8:b000::1), 366 ms
Hop 2:
*
Hop 3:
*
Hop 4:
From 2a00:2302::1103:100:3f, 335 ms
Hop 5:
From 2a00:2380:3013:8000::3a, 344 ms
Hop 6:
From 2a00:2380:13::7b, 326 ms
Hop 7:
From 2a00:2380:2001:7000::19, 342 ms
Hop 8:
From 2a00:1450:8000:266::1:1, 438 ms
Hop 9:
From 2001:4860:0:1::232e, 340 ms
Hop 10:
From 2001:4860:0:1::2482, 333 ms
Hop 11:
From 2001:4860::c:4000:dd7a, 324 ms
Hop 12:
*
Hop 13:
From 2001:4860:0:1::259, 345 ms
Hop 14:
From lhr35s01-in-x0e.1e100.net (2a00:1450:4009:801::200e), 32 ms
Traceroute complete: 14 hops, time: 36911 ms