Automatic should work but for a long time now it has not been working as expected. You switch from Automatic to Manual update within LibreELEC Settings option.
Go to Updates
Automatic updates: Select Manual
Update Channel: Select LibreELEC-9.2
Select Available Versions option and you should be able to both see and select 9.2.1
(You will note advice provided on your current version and version you plan to upgrade/downgrade to)
Yes to update
Then your device will download and update to selected version.
done 
thank you very much
There is no option to select manual updates, only automatic, notify and never check
There is no option to select manual updates, only automatic, notify and never check
I think you have been looking in the wrong places.
Ah, glad I found this. I was wondering if something was wrong with auto updates.
