Configure Grafana in Active-Passive mode


We have two Grafana instances which are using the same MySQL storage but different Prometheus data sources.
The current issue which we have: once we configure alert in one Grafana it will be automatically synced with another one and alert will be executed in both Grafana.
Since Prometheus instances are different we can have the situation when in Grafana A we have metric with value 100 and in Grafana B the same metric with value 0.
If we have the threshold like: alert if value is more than 1 - Grafana A will execute the check and generate the alert but next time Grafana B will execute it again and says that all is good and alert will be resolved.

Please help to understand how to disable alert engine in one Grafana or maybe you have some better idea to improve it.