22:26:04.066745 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8257283, win 232, length 0
22:26:04.066749 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8260163, win 221, length 0
22:26:04.066753 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8263043, win 210, length 0
22:26:04.066758 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8265923, win 199, length 0
22:26:04.066761 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8268803, win 188, length 0
22:26:04.066765 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8271683, win 177, length 0
22:26:04.066768 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8274177, win 168, length 0
22:26:04.066772 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8277057, win 157, length 0
22:26:04.066787 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8279937, win 146, length 0
22:26:04.066791 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8282817, win 135, length 0
22:26:04.066795 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8285697, win 124, length 0
22:26:04.066799 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8288001, win 115, length 0
22:26:04.066890 IP6 2405:.62467 > 2404:6800:400b:c005::86.https: Flags [.], seq 8315445:8316885, ack 30, win 1024, length 1440
22:26:04.067380 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8290881, win 104, length 0
22:26:04.067383 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8293761, win 93, length 0
22:26:04.067385 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8296641, win 82, length 0
22:26:04.067387 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8299521, win 71, length 0
22:26:04.067389 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8302401, win 60, length 0
22:26:04.067391 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8305281, win 49, length 0
22:26:04.068041 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8308161, win 38, length 0
22:26:04.068043 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8311041, win 27, length 0
22:26:04.068518 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8313325, win 19, length 0
22:26:04.069028 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8315445, win 11, length 0
22:26:04.075222 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8316885, win 6, length 0
22:26:04.075452 IP6 2405:.62467 > 2404:6800:400b:c005::86.https: Flags [.], seq 8316885:8318325, ack 30, win 1024, length 1440
22:26:04.084113 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8318325, win 1, length 0
>> (3 second lag)
22:26:07.256847 IP6 2404:6800:400b:c005::86.https > 2405:.62467: Flags [.], ack 8318325, win 1157, length 0
22:26:07.257084 IP6 2405:.62467 > 2404:6800:400b:c005::86.https: Flags [.], seq 8318325:8358645, ack 30, win 1024, length 40320
22:26:07.257200 IP6 2405:.62467 > 2404:6800:400b:c005::86.https: Flags [P.], seq 8358645:8381685, ack 30, win 1024, length 23040
22:26:07.257265 IP6 2405:.62467 > 2404:6800:400b:c005::86.https: Flags [.], seq 8381685:8391765, ack 30, win 1024, length 10080
22:26:07.257311 IP6 2405:.62467 > 2404:6800:400b:c005::86.https: Flags [.], seq 8391765:8424885, ack 30, win 1024, length 33120
22:26:07.257424 IP6 2405:.62467 > 2404:6800:400b:c005::86.https: Flags [P.], seq 8424885:8445045, ack 30, win 1024, length 20160
22:26:07.257460 IP6 2405:.62467 > 2404:6800:400b:c005::86.https: Flags [.], seq 8445045:8458005, ack 30, win 1024, length 12960
(the normal window size when it's not struggling is ~16000 (~4MB scaled))