The operator generates a custom <distributed_ddl> per CHI (e.g. /clickhouse/{chi-name}/task_queue/ddl) but does not set <replicas_path>. ClickHouse 25.8+ falls back to the default replicas_path from config.xml (/clickhouse/task_queue/replicas), which is in a different subtree. This causes the DDL workers to never pick up tasks, making any CREATE TABLE ... ON CLUSTER hang indefinitely.
related PR request:
Altinity/clickhouse-operator#1922
related issue reported by a customer:
Altinity/clickhouse-operator#1883