Neptune Engine 1.2.1.0 hangs with gremlin javascript client

When using gremlin npm package with exact version 3.6.2 with a brand new Neptune cluster with engine version 1.2.1.0 simple queries hangs even after default timeout from Neptune (2 minutes).

How to reproduce:

Having a lambda within the same vpc and doing the following code in a brand new Neptune cluster with engine 1.2.1.0 (tested instance type was db.r6g.large) running the following code:

const { DriverRemoteConnection } = gremlin.driver;
const { traversal } = gremlin.process.AnonymousTraversalSource;

const dc = new DriverRemoteConnection(GREMLIN_ENDPOINT, {});
const g = traversal().withRemote(dc);
console.log(`First toList()`);
const arr1 = await g.V().toList();
console.log(`First Result`, arr1);
console.log(`Second toList()`);
const arr2 = await g.E().toList();
console.log(`Second Result`, arr2);

Even though it's an empty cluster both traversals will not work hanging forever (until lambdas time is out) even though timeout is configured to 2 minutes in the query level within neptune_query_timeout.

The same code running against a Neptune cluster with engine 1.2.0.2 works normally.