Couchbase running at 40-120% CPU with no readers or writers?

I’m running Couchbase (Enterprise Edition 6.0.3 build 2895 ‧ IPv4) using docker-compose. I have 5 empty buckets but nothing is writing to, or reading from them. “top” shows Couchbase is running at 40-120%CPU? Here’s my docker-compose file:

  couchbase:
    build:
      context: .
      dockerfile: couchbase/Dockerfile
    ports:
      - 8091:8091
      - 8092:8092
      - 8093:8093
      - 8094:8094
      - 11210:11210
    networks:
      - couchbase-tier
    volumes:
      - couchbase-data:/opt/couchbase/var

Any ideas how to debug this? I’m browsing the logs but I don’t see anything obvious. Thanks