Snowflake - JDBC error for long running query

Dear experts,

I have an issue with a long running on Snowflake via Knime.

I can connect without problems and query Snowflake but if the query runs approx. more than 5 minutes, I receive an error:

Execute failed: JDBC driver encountered communication error. Message: Exception encountered for HTTP request: ….snowflakecomputing.com:443 failed to respond.

On Snowflake directly, the query is running and takes about 7 minutes.

I have experimented with JDBC parameters (CLIENTSESSIONKEEPALIVE, CLIENTSESSIONKEEPALIVEHEARTBEATFREQUENCY), with setting parameters (ALTER SESSION SET STATEMENTTIMEOUTIN_SECONDS = 7200) and with advances settings (“Automatically reconnect to DB” and “Restore database connection”). Nothing helps so far.

STATEMENTTIMEOUTIN_SECONDS is default 2 days.

Colleagues assume this to be a Firewall issue? Could this be? Or could a Knime setting help?