Reproduce:

• Set phone to Dutch locale, with numbers formatted with decimal comma instead of point.
• Latitude will shows as 52,54322 (with comma) - that's good
• Click on latitude
• Error messages shows "Must be number"
• Tries to parse as number with decimal point
• Entering with decimal point works, but is not logical.
  The input should either accepts both point and comma, or follow the locale for the formatting.