Accessory changes port every restart of Homebridge: problems in firewalled environment

[gandalfk7]

Is your feature request related to a problem? Please describe.
Hi, I am trying to use this plugin but I've noticed that everytime homebridge, thus the plugin, is restarted the accessory port changes.
In the debug is this line:
[accessory name] [accessory ID] is running on port 35056.

Unfortunately in an environment with different network contests divided by a firewall the change would mean to reconfigure the networks every time.

When I open the port it works correctly.

Describe the solution you'd like
If it would be possible to choose in the config on which port to run the plugin it would be perfect.

Describe alternatives you've considered
Cannot think of another workardound

Additional context
None.

thanks for your work!