What Are The Reasons Why IFTTT Doesn’t Work For Two Similar Posts On The Website?

In Semantic Mastery's weekly Hump Day Hangouts episode 309, one viewer asked about the reasons why IFTTT doesn't work for two similar posts on the website.
The exact question was:
Hi Guys! I have 2 questions. 1) Ifttt doesn't work when I'm posting (not updating) the same post on the website. What can be the reason?
