my apple watch won't tell me to stand

Hi

Stand credit can be earned once within each hour. If you have not earned Stand credit by 10 minutes to the hour, then Apple Watch provides a reminder. If you have already earned Stand credit within any given hour, then no reminder is provided.

If reminders are not being provided as expected, then it may help to follow these steps (check after each):

If you have not yet done so, update your iPhone and Apple Watch to the latest software, starting with your iPhone:

• Update the iOS software on your iPhone, iPad, or iPod touch - Apple Support
• Update the software on your Apple Watch - Apple Support

Check your settings:

• On your iPhone, in the Watch app, go to: My Watch (tab) > Activity:
  • If it is currently enabled, turn off Mute Reminders For Today.
  • Check that Stand Reminders is turned on.
• When viewing the time on your Apple Watch, swipe up on the screen to open Control Centre, then check that Do Not Disturb Mode (crescent moon icon) is not enabled.

Close certain apps and restart both your iPhone and your Apple Watch:

• Close the Watch app, Activity app, Health app and any third-party fitness apps (if open) on your iPhone:
  • Double-click the Home button, then swipe up on each app preview to close the apps.
• Turn both devices off together, then restart your iPhone first:
  • Restart your iPhone, iPad, or iPod touch - Apple Support
  • Restart your Apple Watch - Apple Support

Unpair and re-pair your Apple Watch:

• The Watch app on your iPhone takes a backup of your Apple Watch automatically when unpairing via the app. Choose to Restore from Backup during set up. Most data and settings will be restored, with some exceptions (eg Apple Pay cards, passcode).
• Unpair your Apple Watch and iPhone - Apple Support
• Set up your Apple Watch - Apple Support

More information:

Use the Activity app on your Apple Watch - Apple Support

You're welcome! 🙂