The Nominet specs and Nominet support say that the response should include the full creation timestamp including microseconds in a format such as:

<domain:crDate>2024-04-22T13:11:19.039559Z</domain:crDate>

but my script shows the raw response as being:

<domain:crDate>2024-04-22T14:11:19</domain:crDate>

I can reproduce the results from your script - the frame comes back with whole seconds only for crDate, exDate and upDate. However, I do not see anywhere in the Nominet docs that they claim anything else. Can you provide a link to the documentation which states that domain:info returns microseconds?