After deleting hosts and their zones i have problems with the api cache

Hi together,
i’d delete different hosts with their zones, because the complete customer was deleted.
Now i have a problem with ICINGA.
At first i got this message:
Icinga 2 has been running for 6 minutes and 5 seconds. Version: r2.12.3-1; Last zone sync stage validation failed at 2021-01-13 13:54:45 +0100

If i grep for the deleted zone in “/var/lib/icinga2/api”, i will still find the deleted servers und the old zone.

We‘d setup a ha cluster with 2 nodes in the master zone. Everything worked fine up to the point where i deleted a complete zone.

Can someone tell me what i can do to fix this issue?

This is very strange…
I just looked at the directories in the /var/lib/icinga/api/zones/ directory and and the deleted servers and zones are now gone. We have had the problem since the beginning of January. So it’s not like I just deleted the zones and servers yesterday.

Nevertheless, I would be interested in how to react to such a problem.
I found the following procedure in the forum (On Master 1):

systemctl stop icinga2
rm -rf /var/lib/icinga2/api/{packages,zones,zones-stage}/*
systemctl start icinga2

Before that I would stop the 2nd master first and do the same procedure and leave the daemon stopped for now.

When the master is running again I would push the configuration from the director again.
As soon as on the master 1 everything is ok again, I would start the master 2 again.