Well, AOD may not always work on Galaxy Watch devices.
The display sometimes times out and falls asleep on its own.
Lets see how you might troubleshoot this issue.
If you accidentally enabled any power-saving options, AOD will stop working.
Go toSettings, selectDevice care, tapBattery, and then go toPower mode.
Disable any active power-saving modes and reset your watch.
Clear App Data
Clearing out Galaxy Wearable app data may solve this problem.
This action will help you to flush out the cache and restore AODs functionality.
After you removed the app and plug-in, kickstart your phone and reinstall the apps.
Meanwhile, start your watch as well.
Pair your Galaxy Watch with your phone and peek if the AOD issue is gone.
Some users had to reinstall the Galaxy Wearable app twice to get rid of the problem.
Repeat the steps if the first attempt failed to fix the issue.