AmazonMQ (active/standby) connection to second broker fails

Hi,

I am trying to set up an Amazon MQ Broker in the Active/standby deployment mode.

All connections as well as the ActiveMQ Web Console work perfectly with one of the brokers.

When I restart the active Broker, the standby Broker should become Active. In the logs, I can observe, that this works. The standby broker becomes active and starts all connectors as well as the Web Console. But when I try to access the Web Console of this Broker or the other endpoints, the connection times out.

I have checked the security groups and tried different broker instance sizes.

Why can I only connect to one broker instance and not the other, even if the original instance is down?