My Apple Watch Series 4 frequently has a UI reboot when I tap on an activity notification, almost always the ones that correspond to meeting one or more of the week-based goals. I tap on the notification, and rather seeing details, the Apple icon appears and the UI reboots.
Apple Watch
Try a forced reset;
To force reset your Apple Watch, press and hold both the side button and Digital Crown for at least 10 seconds, then release both buttons when you see the Apple logo.
Try a forced reset;
To force reset your Apple Watch, press and hold both the side button and Digital Crown for at least 10 seconds, then release both buttons when you see the Apple logo.
Apple Watch UI reboot after Activity notifications
