Incorrect timestamp values inserted

[victor-ono]

const now = new Date()

con.ks(
    "insert", 
    "`incoming",
    [
      nodeq.timespan(now),
      nodeq.timestamp(now)
    ]
); 

timespan             timestamp
--------------------------------------------------
0D04:08:00.595000000 2023.08.17D04:08:00.595000064
0D04:08:00.610000000 2023.08.17D04:08:00.610000000
0D04:08:00.612000000 2023.08.17D04:08:00.612000000
0D04:08:00.613000000 2023.08.17D04:08:00.612999936
0D04:08:00.614000000 2023.08.17D04:08:00.614000000
0D04:08:04.616000000 2023.08.17D04:08:04.616000000
0D04:08:04.630000000 2023.08.17D04:08:04.630000000
0D04:08:04.632000000 2023.08.17D04:08:04.632000000
0D04:08:04.633000000 2023.08.17D04:08:04.632999936
0D04:08:04.634000000 2023.08.17D04:08:04.634000000

timespan column values look correct, no "rounding errors". How can I make sure that the timespan part in the timestamp column looks the same?