To report bugs you can head over to the GitHub Bref repository.
You can also join the Slack community to discuss Bref and exchange with the community.
On Twitter use #BrefPHP to follow and post news about Bref.
The full list of contributors to Bref is available here.
Here are a few newsletters related to serverless and PHP. Those are not necessarily related to Bref.
You can subscribe to these newsletters to keep up to date with what's happening in the serverless world.