Hi
The Stand ring in the Activity app does not track whole hours during which you have stood (for example: 12 hours credit does not mean that you have been standing for 12 hours).
For the purpose of crediting the hourly Stand achievement, your Apple Watch instead aims to identify when you have stood up and moved around for at least one minute during that hour.
Apple Watch uses an accelerometer to identify movement, so arm movement equivalent to changing from a seated to a standing position followed by a minute's walk around with your arms swinging naturally should normally help to register this.
Stand credit can only be earned once within each hour of the day.
If you remain concerned that your activity is being misinterpreted by your Apple Watch, then:
It may help to calibrate your Apple Watch, including resetting any existing calibration data (doing so will not erase your Activity history):
Activity-related estimations also depend, in part, on your personal information. To check that this is accurate and to update it over time:
- On your iPhone, in the Watch app, go to: My Watch (tab) > Health > Edit - tap and adjust items, then tap on Done.
If the issue persists, then it may next unpair and re-pair your Apple Watch:
If the issue still persists and you are concerned about a potential hardware issue, then I suggest that you contact Apple Support (remote diagnostics and/or mail-in service may be available, if required), make a Genius Bar reservation or visit an Apple Authorised Service Provider for assistance: