I get 12 hops as well if I force a IPv4 tracert:
tracert -4 -w 200 dns9.quad9.net
Tracing route to dns9.quad9.net [9.9.9.9]
over a maximum of 30 hops:
1 * 3 ms <1 ms dsldevice.attlocal.net [192.168.1.254]
2 18 ms 17 ms 17 ms 99-172-162-1.lightspeed.rcsntx.sbcglobal.net [99.172.162.1]
3 63 ms 19 ms 18 ms 71.147.108.17
4 * * * Request timed out.
5 71 ms * * 32.130.24.49
6 * * 71 ms 192.205.37.10
7 71 ms 25 ms 25 ms dls-bb2-link.ip.twelve99.net [62.115.138.64]
8 * * * Request timed out.
9 98 ms 42 ms 41 ms kanc-b2-link.ip.twelve99.net [62.115.138.75]
10 88 ms 46 ms 42 ms kanren-ic-370571.ip.twelve99-cust.net [62.115.154.143]
11 * 55 ms 41 ms quad9.peer.net.kanren.net [164.113.205.226]
12 41 ms 41 ms 41 ms dns9.quad9.net [9.9.9.9]
Trace complete.
An IPv6 tracert has 4 hops:
tracert -w 200 dns9.quad9.net
Tracing route to dns9.quad9.net [2620:fe::fe:9]
over a maximum of 30 hops:
1 * * * Request timed out.
2 18 ms 23 ms 18 ms 2001:506:6000:13c:71:156:210:25
3 19 ms 18 ms 18 ms 2001:506:6000:13c:71:156:210:14
4 43 ms 44 ms 44 ms dns9.quad9.net [2620:fe::fe:9]
Trace complete.
So, seems to just be affecting the IPv4 route at the moment.