Homey calculates power consumption, also for Hue lamps. But when the lamp is switched off by removing it from the power supply (physical power switch) while the lamp condition was on, Homey continues to report the “on” usage. This while the Hue-App is aware that the lamp is not available.
I would like to have the option that Homey considers an “offline” lamp as a lamp that is “off”, and therefore uses no power in the energy report.
Homey is reporting usage. Hue app report lamp offline.
This behaviour is up to the app to implement it. Also it depends on how the energy data is implemented by the app. If it is by approximation then you have no chance to change this behaviour and would ask athom to consider something regarding that.
If the app reports the consumption directly then the app developer would possibly be able to report zero consumption shortly before the device is flagged as unavailable.
Well, if this is an app from Athom try asking the Support for advice here: https://support.athom.com/hc/en-us/requests/new
If the app is form a community developer then lookup the forum page or github for it and raise an issue.