DBConnector timeout on large dataset fetch in Studio

We’re using the DBConnector action in Studio to pull customer history from our SQL server. It works fine for small tables. When the query returns over 500 rows, the script just hangs. No error, nothing. The connection string is valid. Is there a row limit or timeout setting I’m missing? Here’s the snippet:

{
 "type": "DbConnector",
 "query": "SELECT * FROM History WHERE CustomerId = {{data.customerId}}"
}