Am I "missing posting authority"?? In my case..

I was trying to find out why I sometimes cannot post because of "missing posting authority"...
So that I posted this test page and somehow it is working... lol

Finally, I left my draft for a day and clicked "UPDATE POST" next day. And it worked!

I tried the following things and also have refreshed the page, log out and log in again, reopened the browser, reopened the laptop, cleared the post but nothing helped!
Does anyone know the reason?

• Is that because I copied and pasted my sentence? No.
  

• because of linking URL? No.
  https://en.wikipedia.org/wiki/Steemit

• because of the image? No.