Logging to stdout during node.js tests via pino logger

When I run my mocha test suite locally for my node.js project, my logger (via pino) outputs to the console as expected, but when it runs in CircleCI (docker circleci/node:10.16.3-browsers image), there’s no logger output. I even tried SSHing into the build container and running it there, but still no logger output.

Is there some setting/configuration on the container that prevents it from writing to stdout?
(AFAIK, the logger uses stdout by default)