I guess this is because the strict validation that started October 11th. It looks like it is failing this validation because the url in your columnId “link” is an empty string.
See also (from monday):
From October 11th, 2022, we’ll be validating the JSON you send to update column values. Sending unexpected values will return an error. For example:
To update an hour column, you must send the hour and minute in 24-hour format.
“{"hour":16,"minute":42}”
If you send an unexpected value, for example:
“{"hour":false}”
You will see an error saying that “hour” should be a number and that the “minute” key is missing.
Validation will not only check for expected keys, but for types as well. Sending a string when an integer is expected will result in an error, for example.
If I remove this, the query works. This column is a status column with colors. I guess it now want’s a color specified?
Oddly, the query to create the record in Monday looks basically the same and the record get’s created fine. It’s just when updating the Monday record that the error occurs.