The container is slow to start, why?

If you are using Docker and your $(id -u) or $(id -g) is not equal to 1000, the container needs to check and update file ownership (chown) on every launch. Since the container is ephemeral, the uid/gid remapping does not persist between runs. Only files with incorrect ownership are updated, but the check itself still needs to scan the file tree which can be slow if you have a large Zwift installation.

If speed is still a concern, consider changing your user to match the container’s uid and gid (1000) using usermod.

Podman users are not affected by this since Podman handles uid/gid mapping via user namespaces (--userns keep-id).