I have the galaxy watch and have been having issues with the alarms continuing after I've silenced them on the phone and sometimes notifications will show on the watch long periods of time after I get them on the phone.
Please try clearing the system cache and rebooting your device.
If issue persists, please send us an error report with screenshots from One UI Beta App (Beta Feedback -> Send feedback-> Error Reports -> "Select Category" -> Input frequency and Description" -> Send (Top Right Icon). We appreciate your help for supporting beta program.
