Host online/offline notification via e-Mail not working.

[chris-fh]

I use hothost via docker-compose.yml and Traefik.
It is configured to monitor several webpages.
A test message via gmail plugin and the general mail plugin arrive, although it seems notification emails are not triggered, or at least sent when a webpage changes ist status (online/offline).
The respective options in the gmail oder the general mail plugin are activated (Notify on host_is_offline).
In settings "Host is Down confirmations" was set to default (1) also tried out 0, no notifications so far.

How can I debug this, where may I have made a mistake?

[chris-fh]

On the main page there is "Host monitoring" and "Http/Https monitoring".
I was so far taking about the notifications for "Http/Https monitoring" they dont send out notifications.
While I get "Host monitoring" notifications.