I’m having the exact same issue, the codes match and the homekit was originally set up inside the GUI. I don’t know if it is not respecting the config.yaml file or if there is something else going on.
My problem was that I had the HomeKit integration set up by the GUI, and the configuration from the YAML file was not being picked up. I removed the HomeKit integration from the Integrations Menu; and redid it on the configuration.yaml file, and it was working as expected
Did you find a solution to this not involving the manual configuration? I tried adding the lines about the code in the config file but it does not seem to be possible to use both the integration and manual configuration and since I have more entities to be added to Homekit and I am new to this, I would prefer to stick with the GUI.
Was anybody able to solve this issue of the Homekit GUI not allowing pin code parameter?
I solved it by exposing a HA script which disarm the alrm with the code and then exposed this script as a momentary switch in homekit… but it is not super elegant