Glad @Devaraju Sankruth it got resolved.
As the Poster cannot accept his own answer, reposting your answer to close this thread :
The Web activity PowerBI dataset refresh failure seems to be a temporary / transient issue which seems to have been auto resolved.
And The reason why IF activity is executed because you have set On completion of web activity. So even if the Web activity is success or failure, the IF activity would be executed.