How to change a Tab Title?

Good day people, have been trying to change the tab title for a windows and have been having a bit of a challenge. Have used the standard Windows Management to make the name change on the tab but when I preview, one of the names doesn't change while others did. Is there any other possible way to hard code the name change? I saw that example of greytrix.com but I really don't understand how they came up with the result after trying same on my sandbox environment using same Customer Windows. Just in case, still a rookie with X3. Thanks