Hi there! Can you share an example of your requests for creating the note and for the association? I did a basic test using my dev portal and a test contact and was able to:
Upload a file (to be saved as an attachment on an object record)
Add the file to a Note
Add the Note to an object record
One thing to note about Notes is the date you are showing in your screenshot corresponds to the
`hs_timestamp` property used when you create the Note, not when the Note is associated to an object record. You can verify this by adjusting the ISO timestamp value when you create a Note and then associating the note to your object record (Contact in this case)
the timestamp you are sending when creating the note
running a quick test with a few different values for the `hs_timestamp` property when creating a Note to fully understand how the API behaves in this case
In summary, this endpoint is working as designed, but possibly not as you are expecting it to work.