My app was Pending Developer Release. I released it for Sale in Itunes Connect > got the confirmation Ready for Sale email > second after I received 2 emails saying Developer Removed from Sale > app status is now Develper Removed from Sale... How can that at all happen, when I tapped only the Release for Sale button in iTunes Connect?
Make sure that in Itunes Connect > My Apps > Pricing and Availability > Availablitiy is selected and not "Remove From Sale"
When you added that app to ASC, did you set a release date in the future that you may have forgotten about?
If the app has been removed from the store before and the situation you describe has happened so you need just to wait. The process of returning an app to the store after it has been removed is kind of complicated and takes some time. We faced the same situation and finally, our app returned to the store after 8 days.