Filebeat Docker Autodiscovery stopped working when I upgraded to 8.12.0

@GEownt what are you trying to do with this configuration?
When hints are used along with templates, then hints will be evaluated only in case there is no template’s condition that resolves to true.
In your configuration there is a template with no condition, so it will be always true and hints won't be evaluated.
Are you running filebeat inside a kubernetes cluster?
Then why not use

filebeat.autodiscover:
     providers:
       - type: kubernetes
         node: ${NODE_NAME}
         hints.enabled: true
         hints.default_config:
           type: filestream
           id: kubernetes-container-logs-${data.kubernetes.pod.name}-${data.kubernetes.container.id}
           paths:
           - /var/log/containers/*-${data.kubernetes.container.id}.log
           parsers:
           - container: ~
           - multiline:
              type: pattern
              pattern: '^[[:space:]]'
              negate: false
              match: after
           prospector:
            scanner:
              fingerprint.enabled: true
              symlinks: true
           file_identity.fingerprint: ~

Can you try that?