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

Another point, hosts that were already in a maintenance period do not leave this state, even after the maintenance period is delayed, so items are not collected, with the exception of SNMP agent availability. It is necessary to delete the host and create it from scratch to monitor.

In the last image you can see that only the SNMP item is collecting.