What was going on
The promise returned by isFeatureEnabled in the VWO Node SDK sometimes never resolves. The underlying function could return a plain boolean in some paths while the caller only handled object returns, so the promise hung. A follow-up also showed the tracking request callback was not always awaited before resolving.

What fixed it
Fixed in vwo-node-sdk v1.33.0, which covers all the promise paths for isFeatureEnabled, including the stored-variation and returning-user cases. Update the SDK.