It seems that all Athom HomeKit plugs have the same serial number. This causes trouble in Home Assistant when you configure more than 1 plug. This results in only having 1 entity even though you may have several Athom devices configured in Home Assistant.
I just wanted to mention in case someone else has trouble with this. The issue is also explained here with more details:
In this case I have configured 2 Athom HomeKit plugs in Home Assistant. Notice that both are detected with the same serial number "SN8889704". From the Home Assistant docs I get that this serial number is reported by the device itself. Can you confirm that this is the case? If so maybe we could solve this with a firmware update. Thank you!