How do I stop "Missing AWS Lambda trace data for X-Ray" errors that happen after an INIT_START event?

The lambda's configs:

Logs and metrics (default): enabled
Active tracing: enabled
Enhanced monitoring: enabled

The role's permissions for xray:

"xray:PutTraceSegments",
"xray:PutTelemetryRecords",
"xray:GetSamplingRules",
"xray:GetSamplingTargets",
"xray:GetSamplingStatisticSummaries"

Whenever the lambda hits INIT_START:

INIT_START Runtime Version: nodejs:16.v13	Runtime Version 
ARN: arn:aws:lambda:us-east-2::runtime:redacted

I get an error in the logs:

undefined	ERROR	Error: Missing AWS Lambda trace data for X-Ray. 
Ensure Active Tracing is enabled and no subsegments are created outside the function handler.

Active tracing is enabled so I don't think that's the issue. There is no use of AWSXRay.getSegment. There are no other errors related to XRay in the logs, just the one after INIT_START.

What could be causing this? How do I track it down?

Ensure Active Tracing is enabled and no subsegments are created outside the function handler.

Xray does not support create subsegment outside of user's Lambda function. If user calls API beginSubsegment() NOT in Lambda function, every time Lambda initializes a new sandbox will get this error.

After sorting this out with AWS support there are two possible fixes:

1. Find out all the places in your code where tracing is happening and confirm that it's being implemented properly -- fix if possible

2. Set an env var AWS_XRAY_CONTEXT_MISSING with IGNORE_ERROR value in your code

In my case the first one was in a codebase that was a bit out of my control and we weren't very concerned about the error so I used the env var to just ignore the error in my lambda.