I’m experiencing the same issue on HTTPS using an AWS Bitnami installation, fresh install with v.4.24.0; still experiencing upgrade issues in trying to upgrade to v 4.30.1 and have an open ticket with their platform about this at GitHub - bitnami/vms: Bitnami VMs
I cannot see the site design preview and am also using the Let’s Encrypt SSL certificate that was issued using Bitnami’s SSL procedures.