HA changing default units and doing a partial auto-conversion of historical data?

Configuration
1

I have had a ESPHome device running for about 2 years now that measures the level of water in my sump pump and reports that value in meters. I have not modified the device for a very long time.

I noticed today that HA was showing the value in ‘ft’. Now, I am certain I never changed it to feet, so I can only assume some update to HA has changed the default units? The ESPHome YAML for the device is, and has always been, setting the units to meters:

  # Calculation of sump water level based on sensor current 
  - platform: template
    name: "${friendly_name} Level"
    id: level_actual
    update_interval: 1s
    accuracy_decimals: 3
    internal: false
    state_class: measurement
    device_class: distance
    unit_of_measurement: m

I went into the entity settings and changed the units from the dropdown to ‘m’. And so the preview of the history (which I recall uses statistics data and not the states data) is showing that all values are now correct:
image

But when looking at this history tab (which shows the states data when it exists), all the old data is not converted from the “feet” values except for the values in the past ~15 minutes since I changed the units from the dropdown menu:

image
image545×599 22.5 KB

So…
1: Did something change where HA will select “preferred” units for certain entities?
2: When the units are changed via the dropdown, does HA change what is now recorded in the recorder database and in the long term statistics database?
3: When the units are changed via the dropdown, is HA supposed to change historical data that has already been recorded to the recorder database and the long term statistics database?

Seems like something is very wrong here.

Edit: Since I am feeding this data into InfluxDB, I looked at this in Grafana and can see that the entity changed units on Feb 18th 2024. I am still looking to figure out why, or if I updated something on that date.

2

No. Did you change anything in your profile?

Yes.

No.

3

It turns out the day this happened is the day I started fresh with a hew HA install (but carried over my MariaDB database). So certainly a lot changed. What would need to change in my profile to make this device switch units?

In regards to HA not changing data that is already in LTS, why then does the statistics graph not match the states history graph?

4

Check your language setting in your profile. I believe the default units are taken from that. I use English(GB) and get metric units.