Home Assistant Operating System version
The issue
Supervisor considers Home Assistant Operating System older than the last 4 major releases as unsupported. We generally recommend to always update to the latest Home Assistant Operating System.
On an unsupported Home Assistant OS, Supervisor stops refreshing its update information. This means you will no longer receive updates for any component, including Home Assistant Core or Add-on updates.
The solution
Since you’ve not updated your system in a while, we recommend to create a backup before updating your system. Make sure to download the backup or store it at a remote location.
To resolve this issue, update your Home Assistant Operating System version. Go
to System > Updates to update the operating
system. If you don’t see the update you may have skipped it in the past. To see
previously skipped updates, select the three dots
If your system is significantly out of date you may need to update multiple times to get to the latest version.