Zabbix Maintenance Mode for Host groups not working?

[ITIC007]

Hi community!


I set up a Maintenance period as follows:

####################
Maintenance:

Maintenance type: No data collection
Active since: 2019-12-19 00:00
Active till: 2037-12-31 00:00

Period:

One time only
Schedule 2019-12-19 11:12
Period: 2y 8m 29d


Host and groups:

Host Groups: Cloud Maintenance
####################

However - if I manually moved my host X to the "Cloud Maintenance" host group, is still collecting metrics (as seen in Latest Values) and firing Problems. What could be the reason here?

I am using Zabbix 4.0


Thanks!!

[ITIC007]

Update: It is working, but in my case there was around 30 minutes delay from the time I added the host to the target maintenance host group "Cloud Maintenance" until I see the alerts suppressed and the host with "Maintance" tag--- does anybody know why this happen?

The same happens when I remove the host from the host group. It takes 15-20 mins to get it out from Maintenance mode.

[ITIC007]

2nd Update: I checked the Timer process in Zabbix and is virtually idle all the time! So the bottleneck is not there either.