How to show the time of multiple time zones in Windows 10 start menu

I had the same problem and these are the steps I followed to fix it:

  1. Go to windows settings and select 'Apps'

Apps Settings

  1. Click 'Alarms & Clock' in the list of Apps & features and click 'Advanced options'

Advanced Options

  1. Click 'Reset'

Reset

  1. Remove the existing tiles from the start menu and recreate them in the 'Alarms & Clocks' app