So, these two topic of command/home/garage/door and status/home/garage/door have the same result. because the mqtt-out node has the same topic of the mqtt-in node. this will cause an infinite loop in the flow.
Presumably the messages that your flow sends on home/garage/door/command are instructions to the door -"Open", "Close" etc. ?
Why does your flow send messages on home/garage/door/status?
What device subscribes to these messages?
I assumed that these messages would be sent by the door to indicate it's current state - "Opened", "Closed" etc.
What device publishes the message that your mqtt-in node is intended to receive?
Do you have control over the topic this device uses?
Your MQTT-In node is subscribing to the topic home/Garage/#
The hash # symbol is a wildcard which means the node will accept anything from that point onwards.
Your MQTT-Out nodes are publishing to the topic home/Garage/door/status and home/Garage/door/command
If you write the topics out as a list you can see the overlap. home/Garage/# home/Garage/door/status home/Garage/door/command
So your MQTT-In will react everytime you send a message. An infinite loop has been created.
As @jbudd said you need to adjust the topic names or as @Colin says add a 'Filter'node.