Ok, please also post the docker template(1) of swag or letsencrypt (the one you use), while you are on dashboard of unraid click on both nextcloud and swag/letsencrypt dockers and choose logs(2). post both logs. Also post the config file(3) of nextcloud (located on appdata/nextcloud/www/nextcloud/config/config.php and last post the nginx proxy conf(4) (should be in appdata/swag/nginx/proxy-confs/nextcloud.subdomain.conf (change letsencrypt with swag if you use letsencrypt). PLEA