Hello,

When attempting to create a maintenance window after updating both the Zabbix Server and Frontend to version 6.4.11, it's not possible to include hosts in the maintenance window. All parameters are set, but the indication that the host is in a window does not appear, and triggers continue to be generated normally. The first image illustrates an example created, while the second image demonstrates the outcome where the host remains unaffected. The third image shows that the collection is being carried out normally, even with the window indicating "no data collection"

Host