The error comes from PostgreSQL, not from n8n directly. The cause is how the string is interpreted as an array of JSON elements, not as valid JSON itself.
In PostgreSQL, when passing a jsonb array, a valid JSON string is not enough. It must conform to the syntax of a PostgreSQL array.
In this case, the escaped quotes " inside the name field are causing a conflict by interpreting the string as an array literal, not a jsonb.
Instead of using a jsonb array, insert a JSON string and then convert it in PostgreSQL:
SELECT jsonb_array_elements(‘[{“id”:291035,“name”:“Dana "Scott" Simmons”,“avatar”:“”}]’::jsonb)
If you really need to use a jsonb, you must escape everything:
‘{“{"id":291035,"name":"Dana "Scott" Simmons","avatar":""}”}’::jsonb