Docker deployment on Elastic Beanstalk not gathering NGINX logs - amazon-web-services

Question

According to Amazon's Elastic Beanstalk Multicontainer Docker Configuration docs, I should be able to use mount points to get NGINX logs in the location where Elastic Beanstalk expects them.
Volumes from the container instance to mount and the location on the container file system at which to mount them. Mount volumes containing application content so your container can read the data you upload in your source bundle, as well as log volumes for writing log data to a location where Elastic Beanstalk can gather it.
Elastic Beanstalk creates log volumes on the container instance, one for each container, at /var/log/containers/containername. These volumes are named awseb-logs-containername and should be mounted to the location within the container file structure where logs are written.
For example, the following mount point maps the nginx log location in the container to the Elastic Beanstalk–generated volume for the nginx-proxy container.
{
"sourceVolume": "awseb-logs-nginx-proxy",
"containerPath": "/var/log/nginx"
}
I have done this for two NGINX containers in my app, but EB doesn't deliver the NGINX logs when I request logs.
{
"AWSEBDockerrunVersion": 2,
"containerDefinitions": [
{
"name": "gs-api-nginx-versioning",
"image": "829481521991.dkr.ecr.us-east-1.amazonaws.com/gs-api-nginx-versioning:latest",
"memory": 128,
"essential": true,
"mountPoints": [
{
"sourceVolume": "awseb-logs-gs-api-nginx-versioning",
"containerPath": "/var/log/nginx"
}
],
"portMappings": [
{
"hostPort": 80,
"containerPort": 80
},
{
"hostPort": 443,
"containerPort": 443
}
],
"links": [
"gs-api-v1-nginx:v1"
]
},
{
"name": "gs-api-v1-nginx",
"image": "829481521991.dkr.ecr.us-east-1.amazonaws.com/gs-api-v1-nginx:latest",
"memory": 128,
"essential": true,
"mountPoints": [
{
"sourceVolume": "awseb-logs-gs-api-v1-nginx",
"containerPath": "/var/log/nginx"
}
],
"links": [
"gs-api-v1-atlas-vms:atlas-vms",
"gs-api-v1-auth:auth",
"gs-api-v1-clean-zip:clean-zip",
"gs-api-v1-data-alerts:data-alerts",
"gs-api-v1-proc-events:proc-events",
"gs-api-v1-sites:sites"
]
},
<additional container configs>
]
}
Can anyone see what I'm missing here that's causing the logs not to be gathered?