class 'homeassistant.components.mqtt.sensor.MqttSensor'>) is using native unit of measurement '%' which is not a valid unit for the device class ('volume_storage') it is using; expected one of ['fl. oz.', 'L', 'mL', 'gal', 'CCF', 'm³', 'ft³'] #156163
Description
The problem
It seeems like '%' should be a valid unit for volume storage, where the full capacity isn't known but the "percentage full" is.
It's also complaining about using 'None' as the unit for volume storage; I'd originally wanted to use 'counts' for the raw uncalibrated sensor data.
What version of Home Assistant Core has the issue?
core-2025.11.1
What was the last working version of Home Assistant Core?
No response
What type of installation are you running?
Home Assistant OS
Integration causing the issue
mqtt
Link to integration documentation on our website
No response
Diagnostics information
No response
Example YAML snippet
Anything in the logs that might be useful for us?
Additional information
No response