Today() function not working

[Sanskruti]

Hello,
I have a requirement where i want just todays's date in my default date and when i click on custom button i should be able to change the date for that i used bookmark. 
So for my default date i used dax:
Date_default = today()-1.

And I published this file on service. 

Now the problem i'm facing is, I published this file on 24th august and now when i opened that file now it is showing me 24th august only instead of 29 august.

I'm not getting why it isn't taking today's date? Is it becuse of bookmark?

Thank you in advance.

[miTutorials]

The Dataset needs to refresh only then it is going to refresh the Today() function.