Similar experience here with BT Broadband in the UK.
Used to get 150-160ms from here to the NA data center, now experiencing upwards of 600ms regularly.

Tracing route to 204.2.29.7 over a maximum of 30 hops

1 4 ms 5 ms 3 ms [redacted]
2 9 ms 9 ms 9 ms [redacted]
3 * * * Request timed out.
4 10 ms 10 ms 10 ms 31.55.186.188
5 10 ms 9 ms 10 ms 195.99.127.200
6 * 10 ms 11 ms core5-hu0-0-0-35.faraday.ukcore.bt.net [62.6.201.244]
7 26 ms 25 ms 12 ms 166-49-209-132.gia.bt.net [166.49.209.132]
8 11 ms 11 ms 10 ms 212.119.4.140
9 * 13 ms 11 ms ae-7.r20.londen12.uk.bb.gin.ntt.net [129.250.4.140]
10 * * * Request timed out.
11 247 ms 255 ms 246 ms ae-13.r25.asbnva02.us.bb.gin.ntt.net [129.250.2.111]
12 248 ms 257 ms 263 ms ae-1.r24.asbnva02.us.bb.gin.ntt.net [129.250.2.37]
13 648 ms * 551 ms ae-2.r24.snjsca04.us.bb.gin.ntt.net [129.250.6.237]
14 552 ms 555 ms 569 ms ae-4.a00.scrmca03.us.bb.gin.ntt.net [129.250.7.57]
15 471 ms 493 ms 475 ms xe-0-0-5-0.a00.scrmca03.us.ce.gin.ntt.net [128.241.2.18]
16 494 ms 489 ms * 204.2.29.241
17 551 ms 584 ms 589 ms 204.2.29.7