Lambda function is (sometimes) timing out attempting to access s3 - amazon-web-services

Question

So i am attempting to create a lambda function inside of my vpc that requires s3 access. Most of the time it goes off without a hitch, however, sometimes it will just hang on s3.getObject until the function times out, there is no error when this happens. I have set up a VPC endpoint and the endpoint is in the route table for the (private) subnet, ensured that access to the endpoint is not being blocked by either the security group or NACL, and IAM permissions all seem to be in order (though if that was the issue one would expect an error message).
I've boiled my code down to a simple get/put for the purposes of debugging this issue, but here it is in case i am missing the incredibly obvious. I've spent hours googling this, tried everything suggested/i can think of... and am basically out of ideas at this point... so i cannot emphasize enough how much i appreciate any help that can be given
Update: i have run my code from an ec2 instance inside the same vpc/subnet/security group as the lambda... seems to not have the same problem, so the issue seems to be with the lambda configuration rather than any of the network configuration
try {
const getParams = {
Bucket: 'MY_BUCKET',
Key: '/path/to/file'
};
console.log('************** about to get', getParams);
const getObject = await s3.getObject(getParams).promise();
console.log('************** gotObject', getObject);
const uploadParams = {
Bucket: 'MY_BUCKET',
Key: '/new/path/to/file',
Body: getObject.Body
};
console.log('************** about to put', uploadParams);
const putObject = await s3.putObject(uploadParams).promise();
console.log('*************** object was put', putObject);
} catch (err) {
console.log('***************** error', err);
}
};```