When using .datetime() in jsonpath expressions JSON encoded dates are not parsed, this is coupled with the fact that an error isn’t reported.
I would expect that any date encoded via JSON.stringify() would be parseable in these JSON path functions as that is after all the format that dates are very likely to be in.
If I JSON encode a date I get a value such as "2023-05-22T03:09:37.825Z” .datetime() fails to parse this due to the mircosends and timezone indicator, yet its possible to convert that with
"2023-05-22T03:09:37.825Z”::timestamptz
Example here of the issue, and a stackoverflow post with further discussion.